CERTIORARI TO THE CIRCUIT COURT OF APPEALS FOR THE SECOND CIRCUIT.
Hughes, McReynolds, Brandeis, Sutherland, Butler, Stone, Roberts, Cardozo, Black
MR. JUSTICE STONE delivered the opinion of the Court.
This case comes here on certiorari to review a decree, in a patent infringement suit, of the Court of Appeals for the Second Circuit, which reversed the district court and held invalid Claims 1, 3, 14 and 15 of the Schletter Patent No. 1,713,628 of 1929, for an attachment for flat knitting machines. 87 F.2d 702. The Court of Appeals for the Third Circuit had previously held these
claims valid and infringed in Alfred Hofmann, Inc. v. Textile Machine Works, 71 F.2d 973. The patent is for an attachment for "flat" or "straight" knitting machines, including machines of the "full-fashioned" type. By use of the attachment, as the specifications state, "yarn-guides can be accurately controlled to lay a yarn over a distance less than the full length of a course being knitted, as for reinforcing or for so-called split-seam work wherein sections of fabric are connected by suture seams." The attachment, it is stated, may be used for "fashioning designs, as clocks, upon hosiery."
Flat knitting machines are adaptable to use in the manufacture of full fashioned garments such as stockings, underwear or sweaters. A characteristic feature of the manufacture is that the garment or a portion of it, is knitted in a flat web which, in the course of knitting, is shaped by variation of its width, in such a way that it conforms to the contour of the body to be fitted, when its shaped edges are united in a seam. The desired variations in width are secured through control of the traverse or "throw" of the yarn guide which brings the yarn to the needles of the machine as they knit the web. They may be and usually are set up as multiple units in a single machine capable of knitting simultaneously a number of garments of the same type.
The object of the patented attachment in providing accurate controls for yarn guides laying a yarn over a distance less than the full width of a fabric being knitted, is either to knit an additional yarn over a particular area of the main body of the fabric so as to strengthen it or form upon it an ornamental design, or to insert in it "split-seam work," which is a portion of the main fabric knitted with a separate yarn and forming a distinctive design. The attachment makes it possible to lengthen and shorten the throw of the yarn guide, and thus to form designs with reentrant angles in both reinforcement and split-seam work.
The patented device embraces a rotatable spindle having threads cut upon it, in reverse, on opposite sides of its central portion, with a nut mounted upon each of its two threaded parts and moved by its revolutions so that when the spindle is turned in the one direction or the other the nuts are moved by the reversely threaded screws toward or away from each other. Carried on the nuts so as to move with them are yarn carrier stops which are so adapted and located as to serve as controls to limit the travel of carrier rods which have mounted on them the yarn guides. The function of the mechanism is to control the movement of the stops which in turn control the distance of travel of the yarn guides. This is accomplished by the movement of the stop nuts toward or away from each other by the rotation of the threaded spindle in the appropriate direction.
Movement in conformity to a desired pattern is effected by the transmission of power from the main camshaft of the knitting machine to two ratchet wheels mounted on the end of the threaded spindle, each with an actuating pawl. The two pawls are in such relationship that when one operates its complementary ratchet wheel the spindle will rotate in one direction, and when the other operates its complementary ratchet wheel the spindle will turn in the opposite direction. The operation of the ratchet wheels is controlled by means of buttons, arranged on two endless belts propelled by the main camshaft. The buttons attached to one of the belts serve to actuate a mechanism which pushes both pawls. The buttons affixed to the other belt govern a mechanism that selectively engages one or the other of the two pawls, and thus determines the direction in which the spindle and hence the stops are to move. By suitable spacing of the buttons on the belts, the motion, which is to be imparted to the stops through the intermediate apparatus, is controlled in such fashion as to fix in advance the length of throw
and hence the outline of the design which is to be incorporated in the main fabric by ...