Air heating box for textile machines

Abstract

Abstract An insulated air heating box for treating threads transported by textile machinery wherein one wall of the box is provided with entry and exit slots for each thread together with an adjustable thread loading and guiding means insertable through the same wall between or adjacent to the thread entry and exit slots. The box is also equipped with one or more different heating devices, permitting contact-free heating of the threads and/or direct heating on a contact plate arranged within the box. This invention generally relates to an air heating box for the heat treatment of a plurality of yarns or threads which usually move in approximately vertical direction as they are transported by conventional textile machines, especially in texturizing, stretching, stretch-spooling, stretch-twisting or stretchtexturizing machines. Thus, it is often essential in working with synthetic, thermoplastic polymer filaments, threads or yarns to achieve a continuous heat treatment thereof, e.g. for stretching, twisting or texturizing purposes, the same treatment being simultaneously applied to a large number of threads as they are rapidly transported in the textile machine. For the achievement of uniform quality in each individual thread and also equal quality of all of the threads among one another, it is generally desirable that the threads be exposed to the same temperature at all points during their passage in or through the air heating box. One known air heating box has in its interior a large number of U-shaped, electrically heated tubes or rods arranged perpendicularly and transversely to the longitudinal direction of the heating box, additional heating tubes or rods being provided in the region of the heating box base. Between each pair of the threads running from top to bottom once through the rectangular or block-shaped heating box and the heating tubes or rods allocated to these threads, there is arranged a substantially Ushaped sheet metal screen as a functional element. In this known air heating box, for which the electrical installation is relatively expensive, the air within the box has the desired temperature only at a certain distance from the base of the box. The temperature gradually increases toward the upper zones or areas of the heating box and may then fall off again over part of the box height, especially toward the outer cover or top lid. Under these circumstances, the same heat treatment of an individual thread or yarn from its entry into the box until its emergence therefrom is not fully assured, and for this reason, one cannot expect the same heat treatment to be applied as between different threads. A completely uniform heat treatment of the many threads being processed by a textile machine is therefore quite difficult to achieve, particularly in large industrial machines. One object of the present invention is to provide an air heating box for use in combination with textile machinery for the continuous transport and heat treatment of threads, whereby uniform quality can be imparted to a large number of threads as well as a consistent and equal quality in each individual thread. Another object of the invention is to construct such an air heating box so as to provide an equal air temperature over the length and width of the box and also a more nearly uniform air temperature over thE height of the box. Yet another object of the invention is to provide an air heating box wherein individual transported threads can be readily loaded at any time without disturbing other thread treatment positions in the same box and with only a very minimal disturbance of the uniform temperature pattern within the box. Another object is to provide an economically constructed and maintained air heating box with easily installed base heating elements along or in combination with other heating means including plate heaters or similar contact heating members. These and further objects and advantages are explained in greater detail hereinafter. It has now been found, in accordance with the invention, that such objects can be achieved in combination with textile machinery for transporting many threads through an air heating box by providing a preferably horizontally elongated box which is substantially enclosed to receive the transported individual threads at spaced intervals over its length, said air heating box further including heating means located in a lower base area or zone of the box, thread entry and exit openings in the form of slots in one wall of the box, preferably one of the bottom and top walls thereof, and thread loading and deflecting rod means adjustably insertable through wall openings adjacent the thread entry and exit slots. The air heating box, with openings in the bottom and usually with a gas or vapor outlet in the top thereof, preferably is constructed with its longitudinal side walls extending in a vertically upward converging or tapering relationship so as to promote a horizontal mixing or diffusion of heated air as well as a normal vertically urged flow of air by heat convection. The thread loading and deflecting means at each thread position essentially includes a supporting rod member slidable in a slotted guide tube and a thread guide member or deflecting element such as a pin, roller or the like connected near the inner end of the supporting rod and extending outwardly therefrom into the adjacent path of the transported thread, i.e. as the thread is guided back and forth within said box from the entry slot around the guide or deflecting means and then back out of the box through the exit slot.

Inventors

• 👤 Heinz Treptow
• 👤 Benno Frank
• 👤 Heinz Schippers

Bibliographic Details