US1849138A

US1849138A - Process and apparatus for the manufacture of pneumatic tires

Info

Publication number: US1849138A
Application number: US107073A
Authority: US
Inventors: Harold A Denmire
Original assignee: General Tire and Rubber Co
Current assignee: Aerojet Rocketdyne Holdings Inc
Priority date: 1926-05-06
Filing date: 1926-05-06
Publication date: 1932-03-15
Anticipated expiration: 1949-03-15

Description

H. A. DENMlRE 1,849,138

PROCESS AND APPARATUS FOR THE MANUFACTURE OF PNEUMATIC TIRES March 15, 1932.

Filed May 6, 1926 2 Sheets-Sheet l INVENTOR ALI/901.0 A. DEN/WEE. BY (fl/LIMA) X A TTORNE Y.

March 15, 1932; DENMIRE PROCESS AND APPARATUS FOR THE MANUFACTURE OF PNEUMATIC TIRES ile ay 6. 1926 2 Sheets-Sheet 2 INVENTOR. 744%040 vDavy/1P5. BY (1mm of 1% A TTORNEYS Patented Mar. 15,1932

V harass i STATES HAROLD A. nnrmritn, or AK ON, oni nssrsnon ro THE GENERAL er I COMPANY, or eKeoN, OHI

PROCESS AND ArrARA'rns non THE Application filed May 6,

This invention has for its object the'improvement in the method and apparatus for the manufacture of pneumatic automobile tires, by which the shapingof the rubberized fabric about the core isperformed moreeasily and efficiently thanin the spinning operations which are used almost exclusively atthe present time. The invention is particularly useful in the manufacture of tires from the usual cord fabric, and is especially desirable in the construction of tires of largecross-sectioniand small internal diameter. 7

Inthe process of spinningas now in almost all building'of tires upon cores, the

core is rotated at a high rate of. speed and 'stitchers or spinning 'rollers are pressed againstthe sides of the tire anda'dvanced radially from the tread region to thehead of y the tire, smoothing and applying the loose a folds or skirts "of the fabric to the sides or the core. I The shaping of the fabric about a core requires condensing or circumferential shortening of the fabric. Inthe-mamifacture of smaller tires in which the fullness of the'fabric is not great, this method operates fairly satisfactorily, although "Wrinkling will oftentimes occurat thebeads of the tire. In the larger sizes of-tires, however, the spinning operation is not so successful and it so is necessary incertain sizes to dispense with the machine operations entirely and to revert to the old handmethods,as the spinningop v erations as practiced do not securethe condensation of fabric andabsorption of the fullness as required.

In'the old spinning process tated and the spinning'rollers arepresse against the fabric so that the free and unapplied skirts of the fabric, or. that portion which; approaches the spinning rolle-rs',,is retarded to a certain extent by the rollers. There is, therefore,;a Wave of fabric which is built up in front of the stitcher, and if the amount of fullness to be absorbed is great,-

5 bead ofthe tire. Each wrinkle or fold must the core is ro- V D r r v d which my invention operates are as follows.

this fullness will gradually increase until it= PATENT eases order to obtain a'perfect tire. '7 Theprocess and apparatusof perator in an a Nissan this inven- Y tionoperate upon entirely different prin- .ciples than the old spinning operation and secure "a positivecondensation or "crowding together of the cords or elements of the fabric so that the fullness is absorbedin the shaping ofthe-'fabric about the core. The cords of the fabrica're also 'laid about the core in a moresatisfactory' with the prior method; p 1

Asa result, the buildingis more easily and required in :the s thejcore. V p In the drawings there-is shown'one form of apparatus embodying the invention and adapted'to carry out the proc'essherein .disclosed, it being understood thatothe'r t pes of apparatus may be devised for acc-omp ishing the new and improved results, which are intended to be covered herein. 3

In the drawings: I I Figure 1 is a plan view of tire making machine "constructed in accordance with" the principles of theinvention; "Fig. 2 is a side'viBW; f I

Fig. 3 is a section through the central plane of the 'stitchers; i Fig. 4 is a vert of Fig. 3; and

Fig. 5is an en tended toillustrate the manner inwhich the cords are compacted .byfthestitcher wheels.

Briefly stated, the new principles uponhaping offthe fabric about,

Instead of rotating the core by power applied'to its axis, as in former' practices, the core is 'mountedso that it is substantially freely rotatable upon-its axis during the stitching operation, it being desirable, in some instances, rhoweveryto apply slight retarding actionto the rotation of the corein' order to obtain the most desirable degree of crowd ing together and compacting of the cordsby the action of the stitcher disc. 'Although it correctly accomplished and'no hand wor-kiis larged'se'ction which is inhas been proposed in certain patentsto drive 7 the spinning rollers by separate power, as far as known to methis has never gone into-coms 0"v anner than isobtain'able v 1 mercial use and the spinning rollers have been freely rotatable and driven by the core in all commercial embodiments of tirebuilding machines. By the present method, the spinning rollers are positively driven and, by their rotation, the core is driven in turn, the spinning rollers being forced into driving relation to the core and driving the core through the fabric. In this way, a slight differential speed of travel is obtained between the working face of the stitchers and the applied fabric that acts to compact and crowd the elements of the fabric together, the speed of travel of the working face of the stitcher being slightly greaterthan the speed of travel of the engaged face-of the fabric being, applied to the core. As the spinning rollers are advanced radially of the core, the pull of the rollers upon the fabric, operating against the drag of thecore, pulls or crowds the cords together,- thus condensing the fabric circumf'ere'ntially andtaking up the fullness in the loose unapplied skirts.

It-will'be seen, from the explanation which has been given from the description of the tire building machine, that as each group or body of unapplied fabric passes between the edge of the-power driven spinning roller and the core, the pull on the core exerted through the fabric will cause each cord to shift or be crowded next to its neighboring cord, thus contractingthe skirts of the fabric and securing the desired'condensation which is necessarytotake'upthe fullness in the unapplied skirt. As the cords pass beneath the spinning roller, they are adhesively secured in position against the side of the core, or the underlying layer of fabric, and the fabric is smoothly and evenly applied withoutwrinkles and with a complete elimination of the usual pucke'ring or wrinkling.

It will also be observed that, as the fabric approaches the bead line of the core, the relative: fullness increases. With the prior method of shaping the fabric about the core, there is n'o-provision made for compensating for this additional fullness. With the present method, the resistance to the driving of the core, and therefore the pull of the stitchers, increases as the stitchers approach the bead due to the fact that the core is being driven from a constantly decreasing radius. As a result, the compacting force exerted by the stitchers increases as it is required to take care of'the'additional fullness of material. Since the spinning rollers are preferably driven at substantially, uniform speed during the stitching operation, the speed of the core increases as the stitchers approach the bead by reason of the decreasing radius from which the core is driven. The centrifugal action resulting from the increased speed of rotation of the core and the progressively increasing fullness of the unattached skirt cause the loose skirt of fabric to more closely hug the stitching rollers and a progressively greater zone of fabric is acted upon by the stitcher as itapproaches the bead, which re sults in more desirable distribution of tension on the cords of the fabric over the side walls of the tire carcass.

In order to accomplish the results sought for, the usual metallic stitcher or spinning roller may be used. More efhcient results are obtained, however, by the use of spinning rollers having softer or yielding working edges, asthe flexibility of the stitchers enables a better grip to be obtained upon the fabric, with a more effective crowding or condensing of the cords.

The process is especially adaptable for the manufacture of cord tires, as the fact that the cords are free from one another, having no substantial cross weave, enables the crowding, action totake place more easily and effectively than with the older type of woven fabric formerly used inthe manufacture of tires: It is believed, however, that the advantages arising from the manufacture of cord tires would be obtained, although to a lesser'extent, in the manufacture of fabric tires, as they are known in the art.

Aform of machine which is constructed and designed to carry out the process which has been described, is illustrated in the drawings, in which-the numeral 1 indicates the base or framework of a tire building machine and Qthe core thereof which is supported on the outer endof the core shaft 3; The core shaft has mechanism associated therewith for driving the core at speeds suitable to the application of fabric to the core 2 and for facilitating other conventional operations. Thecore shaft is mounted so that it may be disengaged from the driving mechanism after it is given a preliminary rotation or spin so as to avoid excessive friction between the core and'the stitcher discs when the stitchers arebrought into operation. The drive mechanism for the shaft should be disconnected before the stitchers are brought into action. Suitable mechanism, such as an adjustable friction shoel, may also be provided for imparting any desired degree of drag to the rotation of the core to insure proper compacting and crowding together of the-elements of the fabric being applied thereto.

A layer of cord fabric is indicated at 5, the enlarged section in Figure 5 showing the individual cords6' which are coated and surrounded by the layer of rubber 7 as is customary in the manufacture of tires.

At the side of the machine is located the support 10 for the stitching mechanism, which support is arranged to be swung upon the pivot 11 toward or away from stitching position.

Upon the support 10 is slidably mounted the stitcher carriage 14 which is fed toward or from the machine by afeed screw 15 operated by a hand wheel 16. The carriage l has mounted thereon a pair of brackets 17 which are pivoted on vertical posts 18secured in the carriage 14:- A headed guiding pin 20 moves in the slot 21 on the upper surface of the carriage and guides each bracket 7 '111 1ts oscillatory movement. a

Each bracket is formed with upstanding arms 25 in which is mounted the spinning roller shaft 26, the outer end of-which carries the spinning or stitching'roller 27. Each spinning roller isprovided with a soft or yielding working edge or'surface 28, which of the stitcher. 1

The two shafts 26 are connected together 7 for simultaneous rotation by a pair of meshing gears 32 which are located above the piv ots 18 and are crowned so as to remain in mesh during the pivotal movement of the stitcher brackets. The ends of the arms carrying the stitchers are'yieldingly pressed to-' Ward one another by any suitable means,'a n

, interposed compression spring 35be'ingindicated as one form of such device.

One of the spinning roller shafts is arranged to be driven by a motor 86 mounted upon an extension 37 of the bracket 17, the

motor sh aft having a pinion 38which meshes with a gear 39 on the shaft 26.

The operation of the device will be readilyunderstood by those skilled in the art. The

cord fabric is first stretched about the tread of the core, leaving the skirts or edges thereof free and unattached, as shown in Figure 3. After the core has been given apreliminary whirl so as to set it in motion, the stitching Wheels are brought into contact with the core and gradually fed inwardly. The working edges of the spinning rollers bear against the fabric at the side of the core and drive the core through the medium of the fabric The compression or forcing together of the cords is accomplished by the driving action described and which is illustrated in Figure 5, in which the direction of rotation of the driving stitcher wheel andthe core are indicated by the arrows at and b. The movement of the cords is indicated by thesmall arrows c. It will be observed from this View that when the fabric is out of contact with the stitcher and the'core, the cords stand at their normal or partially separated positions. The stitcher rollers, being of relatively large diameter, preferably from six to ten inches, engage a considerable Zone of fabric in advance of the point of. contact of the fabric withthe core and, because the speed of travel of the stitcher is slightly greater than the speed of travel of the portion of the tire carcass being operated upon,the elements of 1 of tangen cy and increases the cord fabric, or other material from which the carcass is being'built' up, are gradually crowded together to progressively greater of the stitcher. "Theiinc'reased speed of the and greater degree along thelcontacting edge [core and the increased fullness of the'unapmovement of the stitcher against the fabric at such increased angle somewhat increases the'radial tension on the fabric to a'desirable degree. In this way, the stitcher acts upon the cords to shift or crowd them'together and,

plied'ski-rt of the I fabric causethe fabric to :fold' back over the edge of the stitcher rollfers' at an increasing angle as the'stitcherapproaches the bead of the'tire; The forward atthe same time, to properly tension {them and stick them to theside'ofthe core or to the underlying fabric intheir compacted or condensed condition. The flattening'of the working edge of th'estitcher, 'as shown in this view, although not essential, has been foundto materially assist in securing theldesired results. stitcher rollers having their working faces formed-bf yielding or non- V yielding material may be employed as desired. I

It will be noted that the axis of the stitcher is located abovethe axis of the core, as shown 7 by the line X of Figure 2. This is equivalent to placing the stitcher at an angle to the line the dragging action upon the cords.

The stitcher carriage 14 is gradually fed inwardly toward the axis of the Score 2 during the/stitching operation by means of the screw 15 so that the stitching rollers 27 travel in a spiral path over the surface of opposite sides of the core progressively approaching the inner edges thereof."

Furthermore,.it is to be understood that the particular forms of apparatusshown and described, and theparticular procedure set forth, are presented for purposes of explanation and illustration of the invention and that various modifications of said apparatus and procedure can be made without departing from my invention as defined in the appended claims.

What is claimed is 1. In the process of manufacturing tires from cord fabric, the process of shaping fabric about a core which comprises stretch ing the fabric about the tread of the core,

leaving the skirts of the fabric free and unattached to the core, the core being mounted for free rotation, then applying the skirts of the fabric about the side of the core by exerting an inwardpressure and a pull upon the fabric of the skirts transversely of the cords, the pull serving to crowd the cords together, apply them to the side of the core and rotate the core upon its axis, and progressively advancing the action toward the bead line in a spiral path.

2. Tire making apparatus comprising a A new, 133.8

fneel-y rotatable-core, 1101 61? movable towesd th xis pf the c an bea ng aga n t the sides-0f the conew-it i e ge egeins the core,

end means to drive the o ler, the ro l 10- .tetin-g the c re through :th medium t fabric to be applied thereto n 3. Tire m king appa tus c mpri ng a freely rotatable or a o ler ha ing va yi l ing workingsllrf-eee which isp ess again the side of the eore, a d mean to driv th noller and thereby rotate the core through the medium of the fabric between the-roller and the core, the noller being movable toward me axis of the qeqre.

. 4. Tire making apparatus comprising a freely vnotaneble core a disk-like roller having n yielding ledge, means for forcing the roller against the side of the core, and means 'fior ,driying' the roller and advancing it toward the axis of the cor nd the y tatingthe ore through t medium of he fabric between the roller end-the core.

In testimony whe of I efi my sig ure- AROLD A- D NMIRE