US3701268A

US3701268A - Air heating box for textile machines

Info

Publication number: US3701268A
Application number: US162082A
Authority: US
Inventors: Heinz Treptow; Benno Frank; Heinz Schippers
Original assignee: Barmag Barmer Maschinenfabrik AG
Current assignee: Oerlikon Barmag AG
Priority date: 1970-07-13
Filing date: 1971-07-13
Publication date: 1972-10-31
Anticipated expiration: 1989-10-31
Also published as: FR2101601A5; CA945353A; CH523355A; GB1299337A

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.

Description

[451 Oct. 31, 1972 United States Patent Treptow et a].

References Cited UNITED STATES PATENTS [54] AIR HEATING BOX FOR TEXTILE MACHINES [72] Inventors: Heinz Treptow,

Ennepetal-Milspe; Benno Frank, Wuppertal-Elberfeld; Heinz Schippers, Remscheid, all of Germany [73] Assignee: Barmag Barmer Maschinenfabrik Aktiengesellschaft, Wuppertal, many Ger- ABSTRACT An insulated air heating box for treating threads transported by textile machinery wherein one wall of the 22 Filed: Jul 13, 1971 [21] Appl'No: 162082 box is provided with entry and exit slots for each thread together with an adjustable thread loading and guiding means insertabie through the same wall [30] Foreign Application Priority Data July 13, 1970 Jan. 22, 1971 between or ad'acent to the thread entry and exit slots. German/"WWI, 20 34 610's The box is also equipped with one or more different 21 02 956-1 heating devices, permitting contact-free heating of the threads and/or direct heating on a contact plate arranged within the box.

[52] U.S. D, 28/59.5, 28/61 [5 1] Int. l/00, D06c 7/00 [58] Field of Search......28/59.5, 61, 62; 68/5 C, 5 D, 23 Claims, 5 Drawing Figures 68/5 E; 57/34 HS -PATENTED our 3 1 I972 SHEET 2 OF 3 ATT'YS 'P'A'TENTED 0m 3 1 I972 SHEEI 3 0F 3 FIG.5

INVENTORS: HEINZ TREPTOW BENNO FRANK HEINZ SCHIPPERS ATT YS 1 AIR IEATING BOX FOR TEXTILE MACHINES 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, stretchspooling, stretch-twisting or stretch-texturizing 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 1 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 U-shaped 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 slotsin 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.

These embodiments and combinations of the invention as well as other preferred variations thereof are more fully illustrated and explained in conjunction with the accompanying drawings wherein:

FIG. 1 is a vertical sectional view of a preferred embodiment of a horizontally elongated air heating box constructed in accordance with the invention, certain elements being shown in elevation or in partly sectional or schematic form;

FIG. 2 is a section taken along the line 2-2 of FIG. 1 to generally illustrate the bottom zone of the heating box, a large central portion thereof being omitted;

FIG. 3 is a plan view of a plate or sheet metal base member adapted to be fastened along the bottom of the heating box to provide thread slots and other reception openings for two thread positions along one side of the box in its longitudinal direction;

FIG. 4 is a fragmented perspective view of a preferred adjustable rod means for loading and guiding and individual thread in the air heating box; and

FIG. 5 is a partial vertical sectional view of another preferred embodiment of a horizontally elongated heating box provided with heated contact plates as additional heating means for the treatment of threads transported in and out of the box by conventional textile machinery.

Referring first to the embodiment of FIG. 1, the overall heating box 1 as a substantially enclosed and insulated casing or housing extending horizontally over a large number of textile machine positions is constructed in a conventional manner of an inner wall or casing 2 and an outer wall or casing 3 with a heat-insulating material 4 enclosed therebetween. These inner and

outer walls

2 and 3 are preferably made of sheet metal, e.g. a lightweight metal sheeting such as aluminum or the like. These sheet metal walls canalso be offset or crimped as well as being provided with structural supports and/or connecting members to give it sufficient rigidity and strength. I

The entire box can be supported on any suitable framework as indicated, usually by a central elongated framework la along the top of a textile machine with thread transporting means such as feed rolls or the like carried 'on either side of this central framework in positions located more or less vertically below the corresponding heat treating positions in the box 1. In some instances, the thread can be supplied from a textile machine located above the heating box so that the embodiment shown must be slightly modified to supply each thread position of the box from above rather than from below. Such modifications will be readily appreciated in terms of only minor changes in the arrangement and construction of individual elements.

Heating elements 5, preferably in the form of two or more tubes or rods 6 and 7 as electrical resistance heating means, are essentially arranged in accordance with the invention along the bottom or base area of the heating box 1. As more fully shown together with FIG. 2, the heating device in its simplest form can consist of two continuous heating elements 6 and 7 extending over the entire length of the box and across the width of each heating section in the form of a loop near the periphery of each longitudinal heating section. The ends of these loops can be connected at a centrally mounted junction box 8 located within or outside of the heating box and supplied with electrical current in a conventional manner from an external source.

The individual threads 9 being supplied from the textile machinery associated with the lower supporting framework la enter into the bottom of the heating box 1 through suitable thread slots and other openings which are described more fully below but which may also serve as inlet means for fresh air. Of course, other openings in the bottom of the box 1 can also be provided for the intake of air, particularly if the thread entry and exit slots and supporting members enter from the top of the box 1. The base installed heating device is essentially devoted to the heating of fresh air entering the bottom zone of the box 1, for example from an ambient room temperature of about 30C. up to the desired air temperature within the heating box of approximately 230C. as but one example. This heating device 5 can also serve to maintain the desired temperature within the box 1 by replacing heat absorbed by the threads or heat lost through expelled gases or vapors and/or by heat conduction gradually through the insulated walls. In this respect, the heat-insulation material 4 contributes substantially to the efiiciency of the device in terms of such heat loss, but the relatively low height of the heating box 1 is also a very significant factor.

The threads 9 enter at the bottom of the box 1 as indicated by the upwardly directed arrow, are deflected near the top of the box and are then withdrawn outwardly in the direction of the downwardly directed arrow on the opposite side of the rod means 10.

Suitably thread entry and exit slots as well as openings for the rod means 10 are thus provided entirely on the entry side of the heating box 1, this being the bottom or base side of the box in the illustrated embodiment. It is equally possible, however, to have the threads enter and leave the top or upper side of the heating box without losing any of the advantages of the invention. In this case, the box can still have its preferred shape in the sense of upwardly converging longitudinal sides, e.g. so as to provide a vertical transverse cross-section of the box interior which has a substantially trapezoidal shape. a

This preferred trapezoidal shape or modifications thereof which permit a gradual reduction of successive interior horizontal cross-sections as one proceeds upwardly in a vertical direction is believed to be at least partly responsible for the surprisingly good results achieved with the air heating box of the invention;

other factors may also be considered as contributing to such successful results which are achieved at relatively low cost in terms of construction and electrical installation and maintenance.

The arrangement of the heating device 5 in the bottom zone of the heating box 1 leads to the result that the air entering at the bottom of the box immediately reaches its desired temperature and, by reason of convection over the relatively short distance from bottom to top of the box, tends to bring theentire region lying above the base to this same temperature, without it being necessary to install additional heating elements above the base.

Through the installation of the entire heating device essentially in the bottom region of the heating box, there also takes place over this bottom area a more or less even heating of the entire inner wall or casing 2 consisting preferably of aluminum sheeting. Since the inner wall 2 is surrounded with a thick heat insulating layer 4 and themetal outer casing 3, the heat loss or rate flow-off to the outside is kept quite low.

The feature of running the thread into the heating box on one side, then deflecting the thread within the heating box and running it out again from the entry side should also participate in the overall desired result, Le. a practically equal temperature over the entire interior of the box. Thus, with heating means disposed in the bottom zone, the air temperature over the height of the heating box is maintained constant more easily as the height of the heating box is reduced. In this sense, the transport of the thread in and out of the heating box on the same side, e.g. the bottom or top of the box, has an advantageous efi'ect. With equal thread running length within the heating box as in known boxes, the height of the box can be considerably reduced even with only one traverse of the tread between the top and bottom of the box. Thereby, the structural height of the entire textile machine in which the air heating box is installed can also be reduced in a most advantageous manner.

It is also most desirable for the maintenance of a substantially constant air temperature in the heating box to simplify the threading or thread-loading procedure so that the introduction of a transported thread can be carried out in the shortest possible time. This third measure which is essential to the invention, namely fastening a thread guide or deflection means to an adjustable rod whereby the thread can be introduced into the heating box andthen held therein in a specific path, permits the thread to be quickly loaded or applied in its proper heat-treating position without the temperature equilibrium being appreciably distrubed. This thread loading or inserting means equipped with a guide or deflecting element on an adjustable rod is described more fully below.

A preferred embodiment-of the air heating box according to the invention is also characterized by an interior horizontal cross-section which essentially diminishes upwardly in vertical direction. Through such a cross-sectional tapering of the heating box from the bottom upward and the oblique or converging walls provided by this construction, there results a further temperature equalization. In particular, the converging longitudinal side walls contribute to the extent that the heated and rising air receives an appreciable horizontal flow component, so that there takes place a temperature balancing effect between the two halves of the heating box across the longitudinal central or bisecting vertical plane.

For reasons of construction and manufacturing, the cross-sectional tapering is best carried out in such a way that the vertical cross-section has a trapezoidal shape perpendicularly to the longitudinal mid-plane or bisecting vertical plane along the longitudinal and horizontal axis of the box. The trapezoid is preferably an isoceles trapezoid, i.e. as represented by the longitudinal side walls providing spaced treating positions in each half of the heating box separated by the midplane.

In order to achieve a temperature balancing in the longitudinal and horizontal direction of the heating box, i.e. over the entire sequence of spaced thread transporting or treatment positions, a further preferred embodiment of the air heating box is characterized by the heating device consisting of a plurality of heating elements extending over the entire length of the heating box. If one of these heating elements should drop out or fail to function, then the heat output of the intact heating elements can be adjusted individual heating elements illustrated, they means of a central temperature sensor or thermostat in such a manner that the desired temperature is maintained. In addition to the single set of individual heating elements illuatrated, they can also run horizontally next to one another or over one another in the bottom portion of the box. Frequently it is expedient to unit the heating elements into a single element encompassing the entire heating box length and width, i.e. as with the looped elements illustrated. ln all cases, these base heating elements are maintained free of contact with the running threads.

The above-mentioned measures all provide a better temperature balancing in vertical and/or horizontal direction and are therefore ideally combined for optimum effect. As stressed, at the outset, however, in loading or applying the thread into the heating box, care must be taken that the temperature equilibrium within the box is not overly disturbed.

In order to accomplish a threading or loading of a stationary or running length of thread or yarn into the heating box both surely and rapidly, the invention includes an especially preferred embodiment of the loading and deflecting means 10 in the form of adjustable rods 12 which can be inserted into or extracted from the heating box 1 while being guided or held slidably in a relatively close-fitting guide tube 11 which preferably has a square cross-section as shown most clearly in FIG. 4.

This guide tube 11 is preferably detachably fastened at its upper or inner end by inserting it into a sleeve or socket member 13 fixed on the upper cover or top side of the box, e.g. using any suitable means to anchor the guide tube in this socket so that it can subsequently be detached and withdrawn if necessary for periodic cleaning or maintenance. At the bottom or on the exterior of the entry side of the box 1, the guide tube 1 l is preferably held firmly in place by a collar or releasable locking clip 14, the tube 11 then extending or projecting downwardly from the box 1 for a distance of preferably in the range of about one-third of its total length.

If the threads enter and exit through the top of the heating box, it is obviously feasible to introduce the rods 12 downwardly in guide tubes 11 from above the box and to withdraw these rods upwardly. However, since the heating box still preferably retains its trapezoidal shape with longitudinal side walls tapering or converging in an upward direction, it is expedient to displace the adjustable rod means 10 alternately on each side of the box at offset longitudinal positions, i.e. alternately parallel first to one side wall and then the other side wall. This avoids any interference when withdrawing rods simultaneously from both sides of the box in adjacent positions or approximately opposing positions. Also, minor variations are obviously required as to the placement or arrangement of other elements to avoid any possible interference with the function of the loading and deflecting rod means.

Each guide tube 11 which fits into the square opening 15(FlGS. 2 and 3) has a longitudinal slot lla along one edge thereof as shown in detail in FIG. 4. Through this slot which appears over substantially the entire length of the guide tube 11, there extends a supporting bracket or cantilever arm member connected rigidly to the upper or inner end of the rod 12 so as to carry at an extended position a suitable thread guide or deflecting member such as the small roller or pin 16b (this deflecting or guide means being indicated at 16 in FIG. 1 wherein the slot 11a is not illustrated). The thread 9 travels upwardly to this guide or deflecting pin 16 in the rising path 17 and then returns therefrom in the descending path 18.

The threading or loading of each thread treatment position along the length of the heating box and on either side thereof takes place essentially as follows. First, the rod 12 is drawn out by its handle 19 after first releasing the safety catch 20 which fits into an opening or recessed arresting hole 20a in the side of the guide tube 11. This safety catch is spring urged on a pivot within handle 12 as indicated so that it automatically locks this rod when shifted or shoved into its fully inserted position in the slotted guide tube 11. When the rod 12 is completely withdrawn, the guide or deflecting element 16 protruding or connected through slot 1 la is also lowered beneath the bottom of the box through suitable openings so that it is readily accessible for thread loading. Thus, the thread is simply placed on or looped over the upper surface of the pin or roller 16a and this deflecting means is then shoved upwardly with the adjustable rod 12 until the safety catch or latch means 2% again locks this rod in its normal operating position with theguide element 16 near the top of the heating box as indicated in FIG. 1. Y

The bracket or arm 16a carrying the guide pin or roll 16!; is advantageously fastened at the inner or free end of adjusting rod 12 so as to run approximately parallel to the longitudinal axis of the heating box 1 as can be generally perceived from the arrangement of parts including their corresponding openings or slots in the bottom of the heating box, all as shown in FIGS. 1-3. Thus, while the rods 12 are inserted at a'slight angle to the vertical, the thread guide element 16 is moved up and down with the guided thread remaining in a substantially vertical plane transverse to the longitudinal axis of the heating box.

The slight inclination of the guide tubes 11 for slidably inserting and withdrawing the rods 12 has the further advantage that the rods can be fully withdrawn without running-into or interfering with thread run-off spools or winding bobbins or the like (not shown) which are usually mounted directly below the heating box 1 on the textile machine frame 1a as further indicated by the inwardly directed path 18 of the downwardly directed threads leaving the heating box. The same advantage applies where the threads enter and exit at the top of the heating box with reference to feed and/or winding spools on an upper machine frame.

In both instances, the rods 12 preferably travel parallel to the longitudinal shanks or sides of the trapezoidal box.

The most ideal construction of the heating box 1 to accommodate this preferred inclined adjustment of the thread guide and loading rods 12 is one in which the wall or side of the box containing the thread entry and exit slots consists essentially of two halves or separate longitudinal bottom wall members abutting on a longitudinal central plane or vertical midsection of the box and extending obliquely therefrom out to join at a right angle with the longitudinal side walls extending parallel to the longitudinal axis of the box. The guide tubes 11 with adjustable rods 12 can then be easily arranged perpendicularly to each half of the bottom wall in positions adjacent their respective thread entry and exit'slots.

Still another advantageous feature of the invention is to provide a heat-insulating or protection tube 21 as shown in FIGS. 1 and 4 which rests freely slidable on the bottom end of the guide tube 11 and is preferably perforated to increase its cooling or protective effect. When the rod 12 is in its fully inserted and normal operating position, this additional protective tube 21 is seated on a stop 12a which travels a short distance into the exposed slot 11a of guide tube 11. Then, when the rod 12 is drawn downwardly, the heat protection tube 21 likewise slides freely downward until its inwardly protruding upper flange or lip 22 comes to rest on the stop members 23 at the lower end of the guide tube 11. (See FIG. 1 for these stop members 23 which are enclosed at the lower end of perforated tube 21 in the closed position of the rod means 9 in FIG. 4.)

This telescopic arrangement of the outer heat-protection tube 21 encloses the outer extension of the interfitting slotted guide tube 11 and the adjusting rod 12 when both the guide tube and its rod are in the fully inserted position, i.e. over approximately one-third'the length of the rod and guide tube assembly. When releasing the safety catch 20 and withdrawing the rod 12, the heat-protection tube 21 slides outwardly over the guide tube 11 so as to always enclose at least that portion of the withdrawn rod 12 projecting immediately adjacent the external fixed end of the guide tube 11. In the fully withdrawn position, one can readily visualize the fact that the tube and rod telescopic assembly extends axially on the outside of the heating box 1 such that the first third of its length is represented by the exposed guide tube 11 down to stop 23, the second third of its length corresponds to the middle third of rod 12 surrounded by the heat-protection tube 21 while the last third of its length is the exposed end portion of the rod 12. In this manner the outer perforated tube 21 effectively shields precisely that portion of rod 12 which is normally contained in the lower part of box 1 and is therefore at an elevated temperature and quite hot after first being withdrawn. in order to enclose all of the upper two-thirds of the withdrawn rod 12, i.e. in-

"cluding its upper one-third which remains within guide tube 11, it is also feasible to divide the protective tube 21 into an upper section 21a retained by stop means 23a and telescopically fitted into the freely slidable lower section 21b, as further indicated in FIG. 4. Nor- 4 mally, however, guide tube 11 provides sufficient heat protection for the withdrawn heated rod 12 immediately adjacent the box 1.

As noted above, the air heating box of FIG. 1 as well as that of the embodiment shown in FIG. 5, has the profile of an isosceles trapezoid in a vertical section transverse to the horizontal longitudinal axis of the box, the smaller base side being on top and the larger base side of the trapezoid representing the bottom of the box. However, rather than providing a horizontal base side, it is especially advantageous to provide a bottom consisting of detachable wall plates or longitudinal segments 24 which can be fastened to extend approximately perpendicular to the respective longitudinal side walls 25 on either side of the longitudinal midsection of the box.

Suitable. inlet pipes or conduits 26 can further be provided, e.g. in side walls 25, for the introduction of steam into the air heating box 1. This improves the heat transition to the threads, especially where a strongheat-tixing effect is desired as in the treatment of torque-crimped threads or yarns.

The trough or gutter formed by the obliquely positioned bottom walls 24 of the box 1 can be provided with one or more discharge outlets 27 for the collection and withdrawal of a liquid condensate, for example steam condensate and/or the condensate formed by finishing agents or the like. The discharge pipe or pipes 27 can be directed away from the textile machine by any suitable connecting line or collecting vessel (not shown).

Most of the vapors or gases arising from finishing agents or the like emerge at the top or cover of box 1 and can be drawn off through a number of outlet apertures 27, for example into a corresponding number of apertures or openings in a suction tube 270 which extends longitudinally over the top of the box 1, preferably on an independent support means 27b without being directly connected to the box so as to provide a slight air gap 28 between the separately supported tube and the cover of the box.

As shown in greater detail in FIGS. 2 and 3, the thread loading and deflecting adjustable rod assemblies 10 are arranged in rows along each of the upwardly converging side walls 25 along the inner wall surface at a distance sufficient to clear the looped heating elements 6 and 7. The individual slidable rods 12 in guide tubes 11 are introduced into the box through the square openings 15 spaced at regular intervals in rows parallel with the longitudinal axis of the box. The square cross-section of openings 15 and guide tubes 11 is selected so that the guide tube will not turn or twist about its longitudinal axis. Any cross-section other than a circular one is generally suitable or else other means must be provided to prevent the undesired twisting.

The enlarged view of FIG. 3 illustrates in detail one plate or segment 24 on one longitudinal side of the heating box 1 and shows the manner in which the threading and guiding elements are received through the bottom of the box 1 in relation to suitably positioned thread entry and exit slots. In particular, an elongated opening or slot 29 extends longitudinally from one of the square tube-receiving openings 15 in a direction substantially parallel to the longitudinal axis of the box, this longitudinal slot being adapted to permit the passage of the bracket or arm 16a of the thread guide means through the bottom of the box. At the same time, the approximately square shaped opening 30 is adapted to receive the thread guide or deflecting element 16b at a relatively short longitudinal interval from the opening 15. In this instance, the square opening 30 is turned so that one diagonal is parallel to the longitudinal direction of the heating box 1 and falls on the longitudinal centerline of slot opening 29. The other diagonal of the square opening 30 leads into a transverse elongated slot which extends from the two transversely disposed corners of opening 30 to provide a thread entry slot 31 and a thread exit slot 32 for the reception of the thread courses or

paths

17 and 18,.

respectively.

These thread entry and exit slots, which are arranged on a common centerline perpendicular to the centerline of slot 29 corresponding to the axis of guide member 16b, should be relatively narrow so as to provide suitable thread guides. For this reason, also, the slots are preferably lined along at least the outer ends thereof with an abrasion-resistant and wear-proof material 33, e.g. very hard surfaced metal coatings or ceramic linings or the like. Since such surfaces are also quite smooth, they prevent inadvertent or undesirable thread damage, e.g. even when the thread is traveling as it is loaded or guided through these entry and exit slots into or within the air heating box.

The elongated opening 29 can continue on as a connecting slot 3 3 from the opposite corner of square opening 3d up to the next adjacent tube-receiving opening 15 which is then associated with another set of openings (29', 30') identical to those first described, including the next set of adjacent transverse thread entry and exit slots (31', 32). In some instances, it is preferable to mount two of the thread guide or deflection elements 161) and 16b in sequence on a single bracket or cantilever arm (16a, 16a) extending from the first described rod 12 longitudinally in slot 29 to reach both openings 31) and 30, for example by merely extending the bracket or arm 16a as indicated by the dotted lines 35 to include segment 16a as part of a single supporting arm, i.e. while omitting the second tube and rod assembly (11, 12).

This means that two thread positions can be loaded simultaneously, i.e. by simply extending the arm 16a beyond guide pin 16b as shown in FIG. 4 to support another guide pin on the same longitudinal axis. Of course, it is also feasible to mount one or more additional brackets and guide means 16 at vertically spaced intervals on rod 12, preferably while offsetting the thread courses slightly and providing separate entry and exit slots for the different thread courses. These and similar variations represent substantially equivalent structures for purposes of the present invention.

The individual plate or sheet metal segment 24 shown in FIG. 3 preferably contains only two up to about four longitudinally spaced thread loading and guiding positions on each side of the midsection of the heating box. Such plates 24 can be in the form of individual panels which are preferably adapted to be inserted in recesses in the outer wall 3 of the bottom of the box 1 and attached to this outer wall or supporting struts thereon or the like by means of bolts or other fastening means through the-bores 36 and 37. Similar openings in the bottom inner wall 2 can be directly provided so as to correspond in approximate shape and location to those of the outer wall 3. The

thread receiving slots

31,32 and 31',32, etc. are preferably made larger in the inner wall 2 so that only those slots in the outer wall 3 serve as thread guides.

Of course, one can also provide these bottom panels 24 in the form of double-walled units with preloaded insulation such that an individual panel extends substantially over its half of the bottom of box 1 or only over an outer portion thereof as indicated by the dotted longitudinal lines 38 in FIG. 2. Thus, such panels or walls can also be hinged or otherwise removably held along inner edge 38 by means of a hinge or holding member 39 along supporting brace 40 of the machine frame 1a (FIG. 1). This permits very easy access to the interior of the box for cleaning purposes or for maintenance, e.g. in replacing heating rods or guide tubes.

The air heating box 41 of FIG. 5 is generally similar to that shown in FIG. 1 in the sense that it is elongated in a horizontal direction and has an inner sheet metal wall 42 and outer wall 43 with suitable insulating material 44 therebetween. However, in addition to a base heating device 45, which is essentially located only in the bottom zone of the heating box and which can again be made up of a number of electrically resistance-heated rods or looped heating elements, supplied with current feed through electrical lines 46, this embodiment of FIG. 5 further includes contact heating plate means 47 and 48 arranged to be placed in direct running contact with the transported thread 49 as it goes upwardly and/or downwardly again out of the box. The heating box 41 also preferably has an approximately trapezoidal shape with upwardly converging longitudinal side walls so as to achieve the desired heating effect from this shape.

The thread loading and deflecting means 50 can be constructed as in the previous embodiment for vertical thread loading but is shown more simply in the present instance as the adjusting rod 51 with a deflecting roller 52 at its upper end and slidably adjusted in the bracket holder 53 by means of rod handle 54. Thus, to install the thread 49, the rod 51 is pulled out until roller 52 is beneath the bottom outer wall 42 for easy application of the thread to roller 52 and reinsertion of the rod 51.

In the illustrated embodiment of FIG. 5, each individual thread 49 is provided on its entry side as well as on its exit side with the

contact plates

47 and 48 which have convex contacting

surfaces

55 and 56, respectively, an are composed of a good heat-conducting material such as any conventional heatable metallic materials preferably with a relatively abrasion-resistant outer convex contacting surface. It is usually desirable to provide for each thread or for a single thread pair only one

contact plate

47 or 48, i.e. so that these contact plates have a width of the thread contacting surface in the longitudinal direction of the box which is quite narrow and sufiicient only to accommodate minor fluctuations in the running course or path of the individually heated thread.

Both

heating plates

47 and 48, as illustrated, have approximately the same construction, but contact plate 47 is free of any other devices so as to be heated solely by the air or gases in the box while contact plate 48 contains a thermocouple 57 and an electrical resistance heating element 58. This permits an additional carefully controlled heating of the thread 49 just before it exits from the heating box, e.g. so that the thread'is very quickly adjusted to a final fixing temperature.

such internally heated plates, i.e. so as to carefully'adjust the temperature indicated by thermocouple 57 over current supply wires 59 to the internal electrical resistance heating element 58. Such temperature control means are not otherwise illustrated since they are usually mounted externally of the machine for adjusting the temperature of a large number of thread treating units.

A ventilation or exhaust opening 66 can be provided in the upper cover or top of the heating box, preferably directly above the guide element 52, to withdraw the vapors of finishing agents and to gradually withdraw air therewith. The thread entry and exit slots 69 as well as the openings for adjusting rod assembly can be partly or almost completely blocked off during operation to adjust air flow into the bottom of the box. One can also provide other air openings with any suitable: means for regulating the size of such openings with respect to the air intake.

Also, access to the interior of the box 41 can be advantageously provided by removable side panels or doors 67 extending over at least a portion of the length of the box. Such panels or doors are removably fastened by the bolts 68 but otherwise provide the double-walled and insulated construction of the remainder of the box. Access for cleaning purposes is generally necessary from time to time because, on the one hand, thread particles such as fluff, lint or dust collects in the heating box and, on the other hand, vapors of textile finishing agents which are usually oily preparation tend to precipitate or condense on the contact plates to form a solid brownish rust thereon which must be periodically removed. Furthermore, worn contact plates or differently designed plates can be changed.

In order to effectively mount and position the

heated contact plates

47 and 48, it is desirable to provide parti- I tions 60 and 61 which extend over the length of the Conventional means for balancing the temperature of heating box 41 and which also consist of a metal or other material of good heat conducting properties so that they can function as additional heat-distributing or temperature-balancing members. In order to permit or allow a certain amount of heat expansion play, these

carrierpartitions

60 and 61 are preferably mounted at only one fixed or stationary point, for example at the top ends thereof by the mounting

brackets

62 and 63, respectively, using any suitable bolt or screw fastening means. Such a fixed point is preferably in the middle of the

narrow partition

60 or 61. This fastening at the upper end only and in the manner shown permits the carrier partitions to expand horizontally in both longitudinal and transverse directions. The outermost partition 60 is of course arranged at a spaced interval from the facing inner side wall 42 of the box, and partition 61 is further spaced inwardly at an appropriate distance.

At their lower edges, the

carrier partitions

60 and 61 are merely guided or loosely held in the slotted or

grooved holders

64 and 65, respectively, which in turn are connected rigidly in any suitable manner to the bottom of the heating box 41. In this manner, the

carriers

60 and 61 are given substantial freedom at their bottom end for heat expansion play. Such means for allowing play to accommodate the effects of heat expansion serve to avoid excessive strain or dislocation of these carriers and the

contact heating plates

47 and 48 which are attached thereto and supported thereby with con ventional fastening means such as bolts, screws, pegs,

tongue and groove connections or any similar means. It

is desirable to provide an intimate or flush contact of the heat-conducting and joined surfaces of

plates

47 and 48 with their

respective carriers

60 and 61.

An identical arrangement of such contact heating plates and carrier partitions with the associated thread loading and guiding elements is contained in the other half of box 41 as only partly indicated in FIG. 5.

These additional contact heating plates for direct heating of the transported threads are of substantial advantage when combined with the base heating elements of the invention in that one can achieve a much more rapid heating of the thread while still maintaining a sub stantially equal temperature over the entire interior of the air heating box.

It is quite often preferable to heat the entering thread exclusively by the heated air, i.e. free of any contact by omitting plate 47 and its carrier 60, since at this point the temperature difference between the air and the thread as it enters is still relatively great so that the heat transfer to the thread by heat convection in air is correspondingly large and effective. Then, by passing the exiting thread over the contact plate 48, it is quickly brought to its final temperature with complete certainty. Such a combination is then ideally suited to high temperature fixing of threads, yarns and similar filamentary materials composed of thermoplastic, synthetic fibrous polymers, especially in crimped or texturized form.

Although the effective contact surface between the running thread and one or both heated convex plates can remain relatively small, the effective contact sur face of these plates with the surrounding air is very great, especially with the cooperation of the additional surface areas presented by the carrier partitions. This assures that the plates remain at approximately the mean or average air temperature in the box, this air temperature in turn being balanced or equalized by the heating plates. The thread is then brought to this same temperature before leaving the air heating box.

With the combined heating devices of FIG. 5, the overall height of the air heating box can be path reduced and a single traversing apth of the thread over the relatively short distance between the top and bottom of the box is sufficient under normal operating conditions to provide an efiective heat treatment of a wide variety of textile threads, filaments, yarns and the like. At the same time, all of the advantages of rapid threading or loading of individual thread treatment positions are achieved without disturbing the uniform and highly equalized or balanced temperature maintained in the air heating box.

The various heating devices and combinations of apparatus shown herein are merely illustrative of the invention and its essential features and characteristics. It is of course a further advantage of the invention that individual elements are relatively easily obtained or fabricated and that the air heating box itself is readily adapted to be used with existing textile machines of all types.

The invention is hereby claimed as follows:

1. In an air heating box for the heat treatment of a plurality of threads being transported by textile machinery in combination therewith, the improvement which comprises:

an elongated and substantially enclosed heating box to receive transported individual threads at spaced intervals over its length;

heating means located in a lower base area of said box;

thread entry and exit slots in one wall'of said box;

and

thread loading and deflecting rod means adjustably insertable through wall openings adjacent said thread entry and exit slots.

2. An air heating box as claimed in claim 1 wherein the bottom wall of said box is provided with said thread entry and exit slots.

3. An air heating box as claimed in claim 1 wherein the top wall of said box is provided with said thread entry and exit slots. 7

4. An air heating box as claimed in claim 1 elongated in the horizontal direction and having an interior horizontal cross-section which reduces in an upward vertical direction.

5. An air heating box as claimed in claim 4 wherein a vertical transverse cross-section of the box interior has a substantially trapezoidal shape.-

6. An air heating box as claimed in claim 4 wherein said heating means includes a plurality of heating elements extending horizontally over the entire length of the box interior adjacent its bottom wall.

7. An air heating box as claimed in claim 6 wherein several longitudinal heating elements are joined to encompass the entire width and length of the box interior adjacent its bottom wall.

8. An air heating box as claimed in claim 1 wherein said adjustable rod means include for each individual thread a slotted tubular guide means fastened to said box and extending between the top and bottom thereof to slidably receive a supporting rod having a thread guide means extending outwardly therefrom and connected near the inner end of the rod to provide a deflection surface around which the entering thread is returned to an exit slot in the entry wall.

9. An air heating box as claimed in claim 8 wherein each said adjustable rod means extends outside of the thread entry and exit wall of the box to provide a slotted guide tube and supporting rod assembly arranged telescopically with an outer heat-protection tube enclosing the outer extension of both said guide tube and rod of said assembly in its fully inserted position said heat-protection tube being adapted to slide outwardly over said guide tube together with the withdrawal of said rod to enclose at least a portion of the withdrawn rod projecting adjacent the external fixed end of said guide tube.

10. An air heating box as claimed in claim 9 including safety catch means locking the telescoping supporting rod, guide tube and heat-protection tube in place in the fully inserted position of said supporting rod.

11. An air heating box as claimed in claim 1 wherein said wall containing said thread entry and exit slots is composed of two halves abutting on a longitudinal central plane and extending obliquely therefrom to receive individual threads on either side of said central plane, each half of said wall forming a right angle with the adjoining side wall extending parallel to the longitudinal axis of the box, and wherein. said rod means are arranged perpendicularly to each half of said wall adjacent respective thread entry and exit slots.

12. An air heating box as claimed in claim 11 elongated in the horizontal direction and having side walls tapering upwardly in the vertical direction to provide an interior heated space which is gradually reduced in volume from the bottom toward the top of the box.

13. An air heating box as claimed in claim 8 wherein said rod means includes a plurality of thread guide means at the inner end of each adjustable rod insertable through a wall opening.

14. An air heating box as claimed in claim 8 wherein means are provided to vibrate said thread guide means.

15. An air heating box as claimed in claim 1 wherein said thread entry and exit slots are lined at the ends thereof with an abrasionand wear-resistant material where the slots are contacted by a running thread.

16. An air heating box as claimed in claim 1 wherein the bottom wall is provided with sufficient inlet openings to admit fresh air for circulation through said box and the upper wall of said box contains outlet openings to withdraw air and any other gases or vapors generated by the heat treatment of the thread.

17. An air heating box as claimed in claim 16 containing means for introducing steam into the interior of the box.

18. An air heating box as claimed in claim 17 having means to discharge liquid condensate from the bottom of the box.

19. An air heating box as claimed in claim 1 wherein the interior of the box is substantially free of air obstructing elements other than said heating means and said rod means so that each thread is transported free of contact back and forth from a thread entry slot to at least one rod-supported deflecting point and then outwardly through a thread exit slot.

16 means permitting heat expansion play.

22. An air heating box as claimed in claim 20 wherein said heating plates contain an electrical resistance heating element.

23. An air heating box as claimed in claim 20 wherein said heating plates contain a thermocouple for regulation of the heat supplied to said threads.

Claims

1. In an air heating box for the heat treatment of a plurality of threads being transported by textile machinery in combination therewith, the improvement which comprises: an elongated and substantially enclosed heating box to receive transported individual threads at spaced intervals over its length; heating means located In a lower base area of said box; thread entry and exit slots in one wall of said box; and thread loading and deflecting rod means adjustably insertable through wall openings adjacent said thread entry and exit slots.

3. An air heating box as claimed in claim 1 wherein the top wall of said box is provided with said thread entry and exit slots. 4. An air heating box as claimed in claim 1 elongated in the horizontal direction and having an interior horizontal cross-section which reduces in an upward vertical direction.

5. An air heating box as claimed in claim 4 wherein a vertical transverse cross-section of the box interior has a substantially trapezoidal shape.

11. An air heating box as claimed in claim 1 wherein said wall containing said thread entry and exit slots is composed of two halves abutting on a longitudinal central plane and extending obliquely therefrom to receive individual threads on either side of said central plane, each half of said wall forming a right angle with the adjoining side wall extending parallel to the longitudinal axis of the box, and wherein said rod means are arranged perpendicularly to each half of said wall adjacent respective thread entry and exit slots.

15. An air heating box as claimed in claim 1 wherein said thread entry and exit slots are lined at the ends thereof with an abrasion- and wear-resistant material where the slots are contacted by a running thread.

20. An air heating box as claimed in claim 1 including a plurality of contact heating plates mounted in the interior of said box and arranged with a convex surface for running contact with each thread.

21. An air heating box as claimed in claim 20 wherein said heating plates are mounted on carrier partitions extending over the length of the box, said partitions being fastened to the inner walls of the box with means permitting heat expansion play.