US3387338A - Metallic card clothing - Google Patents

Description

June 11, 1968 Filed June 3, 196;

HIROYUKI KANAI ETAL METALLIC CARD CLOTHING 2 Sheets-Sheet 1 F/a 9A F/@ 95 FIG 4B F I6 90 FIG 90 June 1968 HIROYUKI KANAI ETAL 3,337,338

METALLIC CARD CLOTHING Filed June 5, 1965 2 Sheets-Sheet 2 vickeris Hardness 8. Side distance IOM. 019/16!" sur ace bOt/p si es Side sur ace a Side distancetfram other Surface both 8/ es ide- SUIfciCG United States Patent 3,387,338 METALLIC CARD CLOTHING Hlroyulri Kauai, 67 Matsunouchj-cho, Ashiya, Japan; Takashi Morikawa, 1551 Higashisonodacho 4-ch0me, Amagasaki, Japan; and Noboru Arita, 12-4 Karigaolra 9-ch0me, Hirakata, Japan Filed June 3, 1965, Ser. No. 461,029 Claims priority, application Japan, Oct. 30, 1964,

39/ 61,693 3 Claims. (Cl. 19114) ABSTRACT OF THE DISCLOSURE Metallic card clothing in which the teeth are made of an inner material between the outer side surfaces of the individual teeth is relatively resilient so that the teeth can withstand repetitive impulse loading during a carding operation. The outer side surfaces comprise an abrasionresistant material that is harder than the inner material. The inner material is exposed along the edges, including the working edge of the teeth and the abrasion-resistant material comprises the marginal edges of the edges of the individual teeth. The resilient core material of the teeth keeps the teeth from breaking due to impulse loading and the hardened surfaces of the sides of the teeth resist wear along the teeth opposite side surfaces. The exposure of the inner material along the edges of the teeth precludes material breaking off of the teeth along the edges.

This invention relates generally to metallic card clothing and more particularly to an improved metallic card clothing having a toothed portion comprising an interior layer of substantially mild resilient structure and opposite side layers of high hardness on both sides of the interior layer.

Conventional metallic card clothing are classified as two kinds as follows:

(1) Metallic card clothing made of high carbon steel having a hardness of Vickers 670-760,

-(2) Metallic card clothing made of certain low carbon steels on which a surface hardening treatment has been applied.

The first mentioned metallic card clothing is resistant to impulse forces but does not have sufficient hardness to withstand abrasion in use, while the second type is resistant to abrasion but does not have sufiicient resistance to impulse forces.

It is clear from the above explanation, contradictory characteristics are required for the practical use of the metallic card clothing.

A principal object of the present invention is to provide a practical metallic card clothing for carding machinery having high abrasion resistance and also sufficient resistance to withstand impulse forces.

Other objects and the novel features of this invention will become apparent from the description which follows, taken in connection with the accompanying drawings, in which,

FIG. 1 is a front elevation view of a metallic card clothing in accordance with the invention;

FIG. 2 is a side elevation view in vertical cross-section taken along section line II-II of FIG. 1',

FIG. 3 is a sectional plan view taken along the line IIIIII of FIG. 1;

FIGS. 4A and 4B are respectively an enlarged sectional side views of a tooth, taken along section line VIVI of FIG. 2;

FIG. 5 is a schematic diagram for explanation of stress distribution in a tooth of the metallic card clothing of the invention under working conditions;

3,387,338 Patented June 11, 1968 "ice hardness of a tooth along the lateral direction taken perpendicularly to the longitudinal direction of metallic card clothing according to the present invention and the conventional metallic card clothing;

FIG. 7 is a graph for explanation of the distribution of hardness of a tooth of another embodiment of the present invention in the same manner as FIG. 7;

FIG. 8 is an enlarged cross section view of a tooth portion of another embodiment of the present invention; and

FIGS. 9A, 9B, 9C and 9D are enlarged sectional views of a tooth portion of another embodiment of the present invention.

For convenience of understanding the present invention, two characteristic features required for long life of metallic card clothing are described as follows, i.e., generally, a metallic card clothing 1 comprises a base portion 2 and a teeth portion 3 as shown in FIG. 1 and FIG. 2. During working operation of carding machinery, fibers are caught by both sides of the tooth portion p and q as shown in FIG. 3 and are dragged or cause to slide on the tooth portion. Therefore high resistance to abrasion is required on both sides of the teeth of the tooth portion for maintaining good working conditions and long satisfactory operating life.

On the other hand, in carding operations, it is quite possible to subject the teeth of metallic card clothing to some unexpected impulse forces. Therefore, if the teeth consist of a brittle material, the teeth portions may be broken by some impulse forces.

It is a main reason why a suitable resilience is required of the teeth structure.

However, the requirements for high abrasion resistance and high resilience of the material of the teeth contradict each other.

To provide the above described characteristics, in the conventional method of manufacturing of metallic card clothing, the two following methods have been applied, i.e., a heat treatment of carbonitriding is applied to the teeth portion of the metallic card clothing to provide a sufficient hardness against abrasion. By this treatment, the structure of the teeth portion is turned to a hard and brittle structure, in which the strucure is uniform. Therefore, the metallic card clothing produced by this method has sufficient abrasion-resistance, but has a defect because of its brittleness and therefore lack of resistance to application of intermittent and repetitive impulse forces.

To eliminate the defect of brittleness, the above metallic card clothing is subjected to tempering so as to provide suitable brittleness, in other words, to provide a suitable resilience to withstand impulse forces. Accordingly, it is clear that the structure of the teeth portion is turned to some mild steel structure or the like, in other words, the hardness of the teeth portion decreases to some extent depending on the tempering process.

Therefore, as these efitects of the treatments are completely contradictory partial conditions of the treatments have been applied in the conventional method for manufacturing of metallic card clothing. The metallic card clothing having Vickers hardness 670-760 provided at the opposite side surfaces of the teeth have been produced for use, in order to satisfy both of the contradictory re quirements half-way.

Another method, i.e., a surface hardening method by carbonitriding has been applied for manufacturing metallic card clothing. This method is applied to the teeth portion of the metallic card clothing made of certain low carbon steel. However, it is diflicult to harden the teeth portion to a sufficient depth, and moreover according to the above treament the whole peripheral surface of the teeth portion of the metallic card clothing turns excessively hard and the inner structure is still kept as a relatively low hardness portion. Under working condition a metallic card clothing is disposed around a cylinder-surface of a carding machine. Whenever an inordinate impulse force is imparted to the metallic card clothing or whenever some trouble occurs, for example due to the presence of some foreign matter of the fibers, an unexpected extra impulse force works mainly upon the teeth portion 3 in a direction indicated by an arrow in FIG. 1. Then some amount of excessive stress is developed in the tooth portion which is explained by a stress-strain diagram shown in FIG. 5. Regarding the stress acting on each cross-section of a tooth portion, maximum stress is developed relative to a working surface x and a rear surface y of each tooth portion, which correspond respectively to x and y of the stress distribution diagram shown in FIG. 5.

Accordingly, if the two working surfaces x and y are composed of a high-hardness structure, as these surfaces are very brittle against unexpected extra forces or inordinate impulse forces, it is quite easy for the working edge surface of the teeth portion to break.

In case a normal carbon steel is used, the brittleness and the resilience vary with hardness, when the above conventional treatment is applied, the tendency of breaking the teeth portion increases. It has been found empirically that the resilience of the teeth portion of the metallic card clothing is not suflicient to withstand impulse forces which occur unexpectedly during working conditions.

In order to overcome the above mentioned defects of the conventional metallic card clothing, the metallic card clothing according to the present invention is provided with a surface layer having a structure of high hardness on both sides of each tooth portion along the longitudinal direction of the metallic card clothing, as shown in FIG. 4A and FIG. 4B, in which a portion corresponds to a high hardness of surface structure and b portion corresponds to a substantially mild structure. That is, both opposite sides of the teeth portion are treated by the various surface hardening methods, prior to the formation of the teeth portion, while leaving a substantially mild or resilient structure as the inner portion of the teeth, or after the formation of the teeth, layers having high hardness on both sides of each tooth portion are provided by the various methods of surface hardening. Therefore, it may be possible to overcome an unexpected extra force or impulse force which acts on the surface x and/or y of the metallic card clothing.

In order to provide a layer or structure having a high hardness on the surface prior to the building up of the teeth portion, almost all the methods now in common use such as carburizing, nitriding, carbonitriding, or diffusion cementation, can be employed. According to these methods, the processing can be done in a sufficient period of time, whereby the surface of the material can be hardened up to 800-850 Vickers hardness.

For example, in a conventional method, carburizing in a smelting tank, filled with a liquid carbonitriding agent which consists mainly of sodium cyanide, especially subsequent to the forming of teeth on the teeth portion, has been impracticable, because of the fusion of the carbonitriding agent disposed between the teeth. However, the same method is now easily applicable for this invention, since surface finishing takes place before the forming of the teeth on the teeth portion. Also, in order to form a layer or structure of high hardness on the surface of both sides of each tooth along the longitudinal direction of the metallic card clothing, after formation of the teeth such methods as electrospark coating, electron beam bombardment, or torch projection, etc., are applicable. For example, in using electrodes of a superhard alloy, a spark discharge is applied with sufficiently high density of electric current to both sides of the card clothing in an air atmosphere or a special gas atmosphere, whereby the superhard alloy is transferred to both sides of the card clothing, and the surfaces of the sides can thus be coated with superhard alloy having a thickness of 20-40 micron or more according to desired requirements, and

thus anti-wear side surfaces of approximately 1,400 of Vickers hardness are developed.

In FIG. 6 and FIG. 7, each line shows the variation of hardness at each position of the tooth portion of metallic card clothing taken along the line VIVI of FIG. 2. In FIG. 6, line A corresponds to a metallic card clothing according to the present invention, line B corresponds to a conventional card clothing, and in FIG. 7, line C corresponds to a case of coating of the teeth by use of high carbon steel according to the present invention, and line D corresponds to a case of coating of the teeth by use of low carbon steel, respectively.

It is clear by the diagram of the variation of hardness, the metallic card clothing according to the present invention has the surface-layers of high hardness on both sides of the teeth along the longitudinal direction of the metallic card clothing and the inner portion of substantially a mild or resilient structure, therefore, the metallic card clothing according to the present invention has an improved quality to overcome the defects of conventional metallic card clothing.

FIG. 8 illustrates a metallic card clothing embodying another form of the present invention. A body of the whole metallic card clothing is made of light alloy or a synthetic resin material having a flexible property and light weight, instead of using a carbon steel as mentioned above, and both sides 5 of each tooth 4 thereof are superhardened by coating them with superhardened-alloy by means of either an electrospark coating method, or a torch projection method, or any other suitable method.

The metallic card clothing thus manufactured has an improved durable character. Since its weight is considerably lightened, the running power of a carding machine and the wear of the bearings are lessened, and further, as the tension for mounting of a card clothing is extremely reduced, the defect of the conventional metallic card clothing, which is to cause strain on the carding machine drum, can be eliminated. Moreover, as an interior portion of the teeth portion has a relatively flexible or resilient structure, even if inordinate forces act on the teeth or if any trouble occurrs caused by foreign matter, the teeth portion is merely bent but not broken and the deformed part can be easily brought back to the original state by using a tool.

The above mentioned embodiments according to the present invention have positively described the case of metallic card clothing having a teeth portion comprising an interior layer of substantially mild steel or other material forming a resilient inner structure and opposite side layers of high hardness sandwiching the interior layer of the teeth portion. However, it is quite possible to construct both sides of the base portion with side layers of high hardness of the same structure of the outer layers of the teeth portion, in the actual manufacturing process, when simplifying the process. Therefore, it should be understood that there is not a clear border line of high hardness of structure extending to the side surfaces of the base portion of the metallic card clothing according to the present invention and in the extreme condition, the whole sides of the base portion of the metallic card clothing may be sandwiched by the above mentioned high hardness structure, as shown in FIGS. 9A, B, C and D. In these figures a portion 6 of high hardness of metallic material, and a portion 7 of mild structure and a portion 88 high hardness of metallic material, are illustrated.

Furthermore, if the tooth edges are caught in one another while the card clothing is being mounted on a surface of cylinder or during working conditions, the teeth are merely bent but not broken.

The embodiments have been described which will fulfill the object of the invention discussed above, but it is contemplated that modification will occur to those skilled in the art which come within the scope of the appended claims and are regarded as part of the invention.

What is claimed is:

1. Metallic card clothing comprising, a base portion and another portion on said base portion having a plurality of teeth formed thereon, each of said teeth having edge surfaces and metallic opposite side surfaces, each tooth comprising an inner synthetic material sandwiched between the metallic opposite side surfaces connected to said base portion, said synthetic inner material having a resilience greater than the metallic side surfaces and rendering each tooth capable of repetitively withstanding impulse loading in operation when said metallic cloth carding is in use in carding machinery, said inner synthetic material being exposed along the edge surfaces of said teeth and an outer abrasion-resistant metallic material of higher hardness and a less resiliency than said inner material directly on said inner material defining said opposite side surfaces of said teeth, whereby the operation and operating life of said teeth is improved and the teeth are able to absorb impulse loading and at the same time withstand abrasion along said side surfaces and the marginal edges of said edge surfaces.

2. Metallic card clothing according to claim 1, in which said inner material comprises a synthetic resin, and in which said abrasion-resistant material comprises a metallic alloy deposited on said synthetic resin.

3. Metallic card clothing according to claim 1, in which said base portion and said another portion comprise a common synthetic material and are integral.

References Cited UNITED STATES PATENTS 20 DORSEY NEWTON. Primary Examiner.

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