US2161742A - Means and method for heat treating wire formed implements - Google Patents

Description

June 6, 1939. G, GASTRlCH 2,161,742

MEANS AND METHOD FOR HEAT TREATING WIRE FORMED IMPLEMENTS Filed Sept. 26, 1936 2 Sheets-Sheet l if fl F M 5- {Z/ENTOR: 5 i 13 lyzzsiiwasfi'ich,

AYYURNEX June 6, 11939. GASTR|CH 2,161,742

MEANS AND METHOD F OR HEAT TREATING WIRE FORMED IMPLEMENTS Filed Sept. 26, 1956 2 Sheets-Sheet 2 Fla-Q5- 5 vii/11m III) 7 INVENTOR.

ATTORNEY.

Patented June 6, 1939 UNHTED STATES PATENT OFFICE MEANS AND METHOD FOR HEAT TREATING WIREv FORMIED IMPLEMENTS Application September 26, 1936, Serial No. 102,752

18 Claims.

This invention relates to a novel method and means for heat treating wire formed implements, such as needles and the like, and particularly spring beard knitting machine needles.

In heretofore attempting to produce needles and similar wire formed implements of uniform molecular structure, in an effort to attain a given standard, it was found necessary to exercise particular care in connection with the length of time that the implements were subjected to a given degree of temperature, during the heat treating process. In addition, it was necessary to exercise strict precautionary measures in conveying the heated implements from the heating chamber to the bath in which they are chilled, to eliminate, as far as possible, the undesirable effects resulting from exposure to air currents during loading and unloading of the container; such exposure occurring in connection with the usual methods of hardening implements of the type set forth. The results obtained by the heretofore practised methods have therefore been more or less variable.

It has also been found that considerable difiiculties are frequently experienced in the use of the multiple section fixtures of the type heretoore employed, at the time that oneof the individual containers was removed from or inserted into the furnace. One such difficulty was due to the air and other matter collecting within the container during its manipulation, while the needles in all of the other open containers were similarly affected by the air which entered the heating chamber coincident with the opening and closing of the furnace door.

The fact that, in the usual prior art containers, one end of the needles immediately contacts the solid heated bottom of the container, whereas the other ends extend toward the cooler part of the container, that is, the part provided with a needle receiving opening, results in unbalanced conditions of temperature in the needles which ob viously tends to affect the uniformity of their molecular structure.

It is an objectof my invention to provide a method of and means for heat treating wire formed implements which eliminates the referred to and other difiiculties hitherto encountered in connection with the heat treating of such implements.

Another object of the invention is to provide a novel method of treating wire formed implements whereby distortion of the implements during heating and/ or cooling will be minimized.

Another object of the invention is to provide a novel structure whereby substantially uniform conditions of temperature will be maintained in the heating chamber so as to bring all portions of the implements to the desired temperature at substantially the same time.

Another object of the invention is to provide novel means for use in connection with the hardening of needle like implements whereby the undesirable effects of oxidation will be substantially minimized.

Still another object is to provide a novel heat treating device of simple construction and which can be quickly and easily operated.

A further object is to provide a fixture for use in the heat treating of needles and the like which may be used interchangeably in different furnaces.

With these and other objects in view, which will become apparent from the following detailed description of one illustrative embodiment of the invention, shown in the accompanying drawings, my invention resides in the novel method and means employed in the heat treatment of wire formed implements, as hereinafter more particularly pointed out in the claims.

In the drawings:

Figure 1 is a perspective view of a hardening furnace with portions thereof broken away to illustrate its operation in connection with the invention;

Fig. 2 is a plan View of the illustrative embodiment. of the invention;

Fig. 3 is a front elevational View of the structure illustrated in Fig. 2;

Fig. 4 is a sectional View of a loaded container member showing a number of needles in correct loading position;

Fig. 5 is a sectional view taken substantially on the line 5-5, Fig. 3, showing an empty rack member preparatory to its being loaded with members of the character shown in Fig. 4;

Fig. 6 isa view similar to Fig. 5 showing the loaded container operatively supported by therack structure and with portions of the container broken away to more clearly illustrate certain features thereof;

Fig. 7 depicts an advanced step in the cycle of operations showing the manner in which the needles are introduced into the quenching bath;

Fig. 8 is an enlarged perspective view of a part of the structure illustrated in Figs. 5 and 6; and

Fig. 9 is a perspective view of a spacer element which forms one feature of the invention;

Fig. 10 is a fragmentary sectional view similar to Fig. 6 but incorporating in the assembly spacer member like that of Fig. 9. i

In accordance with one feature of my invention a rack or support structure is provided within a furnace which is heated by gas, electricity or other means. The rack structure carries a series of hollow members or muffles adapted to receive and support a like number of containers within which the implements to be heat treated are placed prior to the insertion of the containers into the rack structure. Following the loading of the containers they are placed into the rack within the furnace and are there retained for a given period while the temperature within the furnace is maintained within a given range.

Following the subjecting of the implements, to the action of the desired temperature for a given 7 period the loaded container is removed from the furnace and the contents discharged into a bath whereupon the implements are chilled and the molecular structure thereof is consequently set coincident with the quenching operation.

In the present development a rack structure, generally indicatedat' In, Figs. 2 and 3, is provided which comprises a front plate l2, and a back plate l3 between which a series of hollow members or mufiles I4 are supported in parallel spaced relationship, each of members I4 being closed at one end, the left end as viewed in Fig. 5, and open at the other when unoccupied. Leg members l5, l5 extending from the front plate l2 and terminating in foot pieces I6, l6, and leg 'I! which extends from the back plate l3 and which terminates in a foot piece 18, cooperate to form a three-point supporting structure for the rack by means of which the tube elements l4 are unloading of the furnace.

supported in spaced position above a floor IQ of the heating chamber of a furnace generally indicated at 2|].

The furnace 20 comprises acovering 22 which is separated from'the heating chamber by means of insulation 23. A door or gate 24 which is hinged to the top of the furnace, as shown in Fig. 1, is provided with a handle 25 for facilitating opening and closing thereof during loading and The floor or platform I 9 upon which the rack I0 is supported, is spaced above the bottom of the furnace by means of traverse beam members 26, 26, thereby effecting a separate chamber in which the heat is generated. In the present illustrative embodiment of the invention, gas is conducted by a supply line Z'Lto header members 28, 28 from whence it is distributed into the furnace through orifices or nozzles 29 where it burns inthe manner necessaryto heat the furnace to the desired temperature.

Hollow open-ended containers or vessels 30 are provided for receiving a plurality of implements 32, such as spring beard knitting needles and the 7 like, see Fig. 4, These containers are adapted to fit into the hollow members I4 of the rack structure as shown in Fig. 6 and to substantially close their open ends when fully inserted therein. The containers 30 are preferably of open-end construction with a wall 31 spaced intermediate the ends thereby effecting a dual chamber arrangement one compartment 33 of which is used to hold the needles, whereasthe other compartment 7 34 is employed to facilitate manipulation of the A pliers 2| of the type shown in Fig. '7 has been foundto be particularly well adapted for manipulation of the containers 30. This tool comprises a pair of substantially straight members 35 and 36 which are united to a common pivot member 31 at a point intermediate their ends. A spring member 38 is provided to normally keep the tube engaging ends 35a and 36a. in contact, thereby facilitating engagement and withdrawal of these ends from the compartment 34 of the vessel 30.

It has been found from experience that if air is admitted, this will adversely affect the wire formed implements during their subsequent heating by reason of the oxidizing action to which the needles are exposed. Provision is therefore made to hinder air from reaching the inner end of the needle compartment 33, during movement of the container members to and from the furnace. In order to prevent, as far as possible,

air from coming in contact with the needles, it'

ends of the implements, such for instance as' the beards of the needles it has been found expedient to chill the heavier portions first.

Whatever the explanation, experience has shown that it is much preferable to quench the butt ends first. In the case of the needles the beards are preferably inserted into the compartment 33 first, thus, when the needles are discharged into the quenching bath, the butts are chilled first which action has been found preferable, it being understood that not only are the beard ends of less diameter and therefore respond more readily.

and in greater degree to a given internal stress produced in quenching, but the butt ends are clamped when in use in grooved plates which hold them firmly in place for portions of the lengths of the needles, so that their exact hardness is not so important because they are protected from shocks and many stresses.

Upon loading the containers as above set forth it has been found that with the usual structure,

if the needles are kept in the furnace for the period required to raise the temperature of the beards to the desired degree, then the opposite ends will still be too cool to permit proper hard- 7 ening if quenched. Furthermore, if the needles are kept in the furnace long enough to raise the temperature of the butts to the degree desired, then the beards become overheated if the furnace is above the final temperature desired for the needles or the two ends are kept at the maximum or soaking temperature for'unequal lengths of time. These conditions result because of the un-. balanced distribution of heat to the opposite ends of the needles.

This undesirable condition is eliminated in accordance with the present invention by means of a novel structure associated with the rack member In. Such structure comprises a plug or insert member for 1 each container 30. plug or insert member, which is illustrated in Fig. 8 and which is generally indicated by the numeral 40, preferably comprises a solid cylin- This drical piece 4i having a fiat circular plate or disc 42 at one end thereof whereas the opposite end terminates in a tapered portion 43. These plug members 48, one of which is provided for each container 30, are rigidly secured to the back plate It along the axes of the tubes M so as to extend within these tubes in manner best shown in Fig. 5, thereby eifecting a support and a plug structure for the container members 39, Fig. 6. The parts forming the structure shown in Fig. 5 may be joined together by any of a number of well known ways, such for instance as by riveting, bolting, welding, etc.

The plugs or insert pieces All which in the present instance are of metallic construction are constantly maintained at a high temperature due to their being positioned within the heated furnace 29. Now since the plug or insert piece 40 substantially fills the otherwise empty portion of the conta ner 39, see Fig. 6, the amount of heating surface to which the opposite ends of the needles are exposed is substantially equalized, and the diiference in distance between the respective ends of the needles and the adjacent heating surfaces much reduced. Furthermore, the fact that the plug til is always maintained within the furnace results in a slight temperature differential in its favor as compared with the transverse wall 3| of the compartment 33 which becomes slightly cooled during the unloading and loading operations. This condition aids in bringing the heavier butt ends to the required temperature within the time required to similarly heat the needle beards. In addition, what little air is gathered by the container during the unloading and loading operations will be largely expelled upon being brought into contact with the hot plug member it at which time the air is greatly expanded and rarifiecl, thereby substantially eliminating the oxidation of the needles. It will be appreciated that this action takes place simultaneous with the placing of the containers into their respective tubes 14 because of the large amount of heating surface to which the collected gases are exposed.

The active length of the needle compartment 33 and consequently the distance between the plug member or insert piece 30 and the needles may be adjusted by replacing the member 49 with another of suitable length, or by employing spacer elements, such for instance as are indicated by the character 45 in Fig. 9. A provision of this nature is more important in such cases where the gauge and/or the length of the implements to be hardened is changed from time to time and where it is however desirable to establish a definite distance between the plug element 48 and the needles. This arrangement likewise adapts itself to the condition where it becomes necessary to adjust the distance between the plug member fit and the wire formed implements in order to control the heat transmission from the plug member to the implements.

Certain needles within the container are brought to the desired temperature by means of heat conducted to the portions of the vessel with which they are in contact, whereas other needles are raised to the desired temperature by radiated heat. To control the speed with which these implements are brought to the desired temperature, it therefore becomes necessary to establish the proper distance between the insert piece 40 and the implements, and this is accomplished by means of the spacer elements 45 and/or plugs of different lengths. The inside diameter of the spacer elements 45 is made to conform with the diameter of the plug member 40 so that the spacer element may readily be slipped thereover' and positioned between the back plate I3 and the open end of the compartment 33. Consequently, any desired adjustment of the container 30 relative to the insert piece may be obtained by employing spacer elements of different thicknesses.

The method followed in the hardening of wire formed implements of variable thickness, such as spring beard knitting machine needles, in the present instance comprises arranging the implements in a group with similar ends adjacent each other, placing the implements while so grouped into the container or vessel in such a manner that the smaller portions, such for instance as the beards of the needles, are positioned adjacent the closed end of the vessel (see Fig. 4); placing the loaded vessel into the rack within the heated furnace and into telescoping coaction with the heated plug or insert piece; heating the loaded vessel within a given temperature range for a specified period; and removing the vessel from the furnace and introducing the wire formed implements while so grouped, the heavier ends first, into a quenching bath thereby effecting the setting of the molecular structure of the metal. During unloading of the container the open end is preferably placed very close to or below, the surface of a quenching bath M, as shown in Fig. '7, for the purpose of shielding so far as possible, the intensely hot implements from the detrimental effects of the air. The purpose of loading the containers as above set forth is to reduce warping of the needles. Thus by progressively quenching the implements in the manner disclosed, the heavier parts are first subjected to the quenching effect thereby causing the quenched needles to be much less distorted, it being understood that quenching of the needles with the beard ends first would result in undue distortion and especially of the bearded portions, whereas when treated in the manner stated all portions will more nearly retain their original shape.

Of course the improvements specifically shown and described, by which I obtain the above results, can be changed and modified in various ways without departing from the scope of the invention herein disclosed and hereinafter claimed.

I claim:

1. A device for heat treating wire formed implements, comprising an open end receptacle, a furnace structure for removably supporting said receptacle, and a plug member carried by said structure and shaped to fit into the open end of said receptacle and operative to effect a closure therefor.

2. A device for heat treating wire formed implements, comprising an open end receptacle for the implements, a furnace, a rack within the furnace for removably supporting the receptacle when the receptacle is on said rack, and a plug member extending from said rack into the open end of said receptacle.

3. Apparatus for heat treating wire formed implements, comprising, an elongated receptacle having an opening adjacent one end for receiving the implements, a furnace, a rack structure for supporting said receptacle in said furnace, and closure means for said receptacle carried by said rack, said rack and closure means arranged so the closure means closes said opening in the receptacle when the receptacle is on said rack and against said means.

l 4; Apparatus for heat treating wire formed implements, comprising an elongated receptacle having open hollow end portions separated by a wall structure intermediate its ends, one of said hollow portions constructed to receive the implements, a furnace, a rack structure for removably supporting the receptacle in said furnace, and a plug piece carried by said rack structure and closing said implement receiving portion while the receptacle is on said rackand against said means.

5. In a furnace for heating wire formed implements, the combination comprising, a receptacle for the implements, a structure within said 7 furnace for supporting said receptacle, and means carried by said structure and extending intosaidreceptacle and adjacent to the imple-.

ments for conveying heat to one end of the receptacle.

6. In a furnace for heatingwire formed implements and having a floor, the combination comprisinga receptacle for the implements, a rack structure within said furnace for supporting said receptacle in positionspaced from the floor of'the furnace, and a plug member extending from said rack structure into said receptacle and adjacent to the implements for conveying heat to one end of said receptacle.

7 7. Apparatus for heat treating wire formed implements, comprising a furnace, a muffle therein, and an elongated substantially hollow member adapted to be readily inserted into and withdrawn from said muffle and having open ends and 'a wall structure therebetween for effecting a dual chamber structure, one of said chambers operative for holding the implements, and the other chamber being operative to facilitate manipulation of the receptacle.

8. An apparatus for use'in the hardening of wire formed implements comprising a furnace, a muffle therein, and a dual chamber elongated open-end receptacle adapted to be readily inserted into and withdrawn from said muffle, one of said chambers adapted to receive said implements and cooperate with a stationary complementary plug member within the furnace for sealing the implements in the container, and the other chamber being operative for facilitating manipulation of the container.

9. In a furnace for heating wire formed implements, in combination, a muffle of elongated form arranged to receive a vessel therein at one end, and a vessel having an open mouthed chamber for holding implements'to be heated and arranged to be inserted into said muffle, said muffle and vessel having complemental means for closing the mouth of said chamber.

10. In a furnace for heat treating wire formed implements, the combination comprising, a hollow receptacle having a chamber for said implements and having a transverse wall closure'at one end of said chamber, a structure for supporting said r receptacle within the furnace, and means associated with said support and operative for controlling the active length of said chamber.

11. In a furnaceifor heat treating Wire formed implements, the combination comprising a tubelike receptacle for the implements having .a closure at one end thereof, a structure within said furnace for supporting the receptacle above the 12.. Ina furnace for heat treating needles andthe like, the combination comprising a pair of upright plate members arranged in parallel relationship and having separate cut-out portions of like configuration, a tube member having opposite ends thereof respectively secured to said plate members in alignment with said cut-out portions, a generally hollow open-ended vessel of dual chamber construction for insertion into said tube member, and a plug member extending from one of said upright plates centrally of said tube member effecting a closure for said vessel upon positioning of the vessel in said tube member. 7 7

13. In a furnace for heat treating needles and the like, the combination comprising a pair of upright plate members arranged in parallel relationship and having separate cut-out portions of like configuration, a tube member havingopposite ends thereof respectively secured to said plate members in alignment with said cut-out portions, a generally hollow open-ended vessel muffle, and a container of the same general shapeas said muffle for receiving articles to be heated arranged to slide readily into andout of said 1 muffle but with small clearance at both ends to substantially closethe muffle when lying therein, said projection and container arranged so that the projection extends into the container and substantially closes the container when the container is in the muffle, said container having a recess at one end to receive a handling tool.

15. The combination in a heating apparatus of a furnace, an elongated muffle supported in said furnace by a structure having a projection extending centrally and longitudinally of the muffle, said muffle being so arranged in the furnace that said projection is maintained at high temperature, and a container of the same general shape as said muffle forreceiving articles to be heated arranged to slide readily into and out of said muffle with but small clearance at both ends to substantially close the muffle when lying therein, said projection and container arranged so that the projection extends into the container and substantially closes the container when the container is in the muffle and the projection is caused to radiate heat to objects Within the container.

16. The method of simultaneously heat treat- 7 ing a group of elongated Wire formed implements having unlike ends comprising the steps of arranging the implements in a group with similar ends adjacent each other, then heating said group in an elongated compartment of a container, transmitting heat to said container over the major portion'of the length of said wcompartment primarily by'radiation and from all ends of the implements to'surfaces heated primarily by conduction and thereafter introducing 'sides substantially equally while exposing both the implements lengthwise into a cooling bath one end first.

1'7. The method of heating simultaneously a group of elongated wire formed implements having unlike ends comprising the steps of arranging the implements in a group with similar ends adjacent each other and placing said group in an elongated chamber and heating the chamber over the major portion of the length thereof substantially solely by radiation and from all sides substantially equally while exposing both ends of the implements to surfaces heated by conduction.

18. An apparatus for heating small elongated implements comprising a substantially horizontal muflie chamber having a directly heated end and a container having a chamber for the implements and adapted to be readily inserted and removed from said mufile chamber and having contact therewith at said heated end and contact therewith also immediately adjacent the end of its own implement chamber removed from said heated end of the muffle chamber, the sur-- face of the implement container being spaced from the inner surface of the mufiie over much the greater portion of the outer surface of its implement chamber whereby a large portion of the heat received by the implements is imparted to the implement chamber by radiation.

GUSTAV GASTRICH.

CERTIFICATE OF CORFUEC'IIONo Patent No. 2,l6l,7) 2., June 6, 1959.

GUSTAV GASTRICH. It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, sec- 0nd column, line 65, strike out the words when the receptacle is on said rack" and insert the same after receptacle' and before the period in line 67, same claim; and that the said Letters Patent shouldbe read with this correction therein that the same may conform to the record of the case in the Patent Office, I

Signed and sealed this 25th (1a; of July, A Do 1959..

Henry Van Arsdale, Acting Commissioner .of Patents

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