Abstract: A variable diameter gear device for variable ratio transmission systems has a displaceable gear tooth sequence formed from interconnected gear teeth with uniform pitch lying on a virtual cylinder coaxial with an axle of the device. A torque linkage transfers a turning moment between the axle and the gear tooth sequence. A diameter changer includes at least one disc with a spiral track to which each of the gear teeth is linked. Rotation of the discs relative to the axle causes variation of an effective diameter of the virtual cylinder while the gear tooth sequences remain on a virtual cylinder centered on the axis and the uniform pitch remains constant.

Abstract: A variable diameter gear device for use in a variable ratio transmission system includes a gear tooth set deployed around an axle which defines an axis of rotation. The gear tooth set includes at least two displaceable gear tooth sequences, each including a multiple gear teeth spaced at a uniform pitch, and a diameter changer mechanically linked to the axle and to the gear tooth set. The diameter changer is deployed to transfer a turning moment between the axle and the gear tooth set, and to displace the gear tooth set so as to vary a degree of peripheral coextension between the gear tooth sequences. Specifically, the diameter changer transforms the gear device between at least two states in which the gear tooth set is deployed to provide an effective cylindrical gear with differing effective numbers of teeth. The gear device may be used either in direct engagement with another gear wheel or as part of a chain-based transmission system.

Abstract: A method and apparatuses for embedding a resistance heating wire in a thermoplastic element having a surface such as an electrofusion saddle coupler by providing an operating head including heat grooving mechanism and wire inserting mechanism, the operating head and the thermoplastic element being integratively movable in all directions one relative to the other; using the heat grooving mechanism and the relative movement for creating a groove in the surface of the thermoplastic element; and, thereafter using the wire insertion mechanism and the relative movement for inserting the resistance heating wire into the groove, to implant the resistance heating wire in the groove.

Abstract: A small portable drawing-in machine is disclosed for suspension on the top of a loom reed and for movement along the lengths of the reed. A drive screw on the machine meshes with the reed dents to control the position of the machine on the reed, and a threading hook is projectable through the spaces between reed dents to draw warp yarns therethrough. A set of drive screws of different pitches may be replaceably mounted in the machine to give the machine a capability for use on reeds of different pitch.The threading hook is reciprocably mounted on a rotatable turntable that is coupled through suitable gearing to the drive for the drive screw so that a machine cycle includes a movement of the threading hook to carry a warp yarn through a space between reed dents, a rotary movement through 360.degree.