US1388382A - Mold for pneumatic-tire tubes - Google Patents

Description

F. A. SCHWARTZ.

MOLD FOR PNEUMATIC TIRE TUBES. APPLICATION FILED FEB. I0, 1921.

1,388,382. Patented Aug. 23, 1921.

frwezzzar UNITED STATES PATENT OFFICE.

FRED A. SCHWARTZ,'OF BROOKLYN, NEW YORK.

Specification of Letters Patent.

Patented Aug. 23, 1921.

Application filed February 10, 1921. Serial No. 448,917.

To all whom it may concern:

Be it known that I, FRED A. SCHWARTZ, a

citizen of the United States of America, re-

siding in the city of Brooklyn and State of New York, have invented new and useful Improvements in Molds for Pneumatic- Tire Tubes, of which the following specification is an exact and true description, such as will enable others skilled in the" art to which it appertains to make and use the same.

The invention relates to the construction and vulcanization of casings that are usedin combination with pneumatic tubes, the said combination being usually referred to as the pneumatic tire.

The object of the invention is to provide means to correct certain faulty conditions that obtain with ordinary methods of constructing and vulcanizin casings.

In the process of vu canizing casings 1t has been demonstrated that better results are obtainable when the fabric structure ofthe casing is subjected to pressure that is applied in the direction of the radii of the easing simultaneously with ressure that 1mpulses the companion casmg forming mold parts.

To this end various means are being employed, as for example, the casing to be vulcanized is removed from the rigid core upon which it is constructed and there is substituted an elastic core by which means the casing is during the process of vulcanization subjected to an expandlng pressure that is admitted to within the elastic core.

With my invention in use, similar results are obtained, and without the expense of renewing at frequent intervals the elastic cores, and with a considerable saving in time and labor consumed in bolting or clamping companion casing forming mold parts against the internal pressure.

As will be made plainly evident in this specification, by reason of the novel conformation of the surface area of the improved core, and grooves of the companion casing formlng mold parts, the fabric or cord structure of the casin during the process of vulcanization, is, by t e use of my invention subjected to stress that is applied to the fabric or cord structure in the direction of the plane of the side walls of the casing simultaneously to the compressing action of the caslng forming mold parts.-

In the accompanying drawin s which.

form a part ofthis specification, lgure l is a cross section of the vulcanized casing in association with a cross section of the improved equipment; the core and companion casing formmg mold parts which comprise the improved equipment being in their relative operative position as assumed during the final stage of the process of vulcanization of the casing.

Fig. 2 is a fragmentary cross section of the vulcanized casing, illustrating by broken lines the conformation as assumed by the sidewalls of the casing when in use.

Flg. 3 is a view similar to Fig. 2, illustrating the method of building or mounting the unvulcanized casing upon the core.

The improved equipment may be employed in the construction and vulcanization of casings of the clencher, or straight side type, and the core forming a part of the improved equipment may be rigid, or collapsible, and while the equipment is more particularly intended for use in the construction and vulcanization of casings of the cord ply construction, by the use of my improved equipment casings of superior quality may be produced in the woven fabric ply construction.

The function of the improved equipment is positively reliable, and results from the novel method of building or mounting the casing upon the core, and by the conformation given the side walls of the casing during t e process of vulcanization.

The method of building, or constructing the casing upon the improved core is substantially the same as when employing the ordinary equipment; that is the body of the casing consists of several layers, or lies of rubberized fabric or cord, and upon w ich structure the outer elements of the casing, as the tread, beads, and side walls of rubber compounds, are secured by vulcanization.

Referring to Fig. 1, and to the core 2, which may be constructed by any preferred method, as for example it may be cast solid, or hollow, or it may be constructed of pressed metal parts. It will be noted that the surface of the core is provided with circumferentially directed grooves, as indiqualities of therubber cement. As will be cated b the numerals 3, 3; it will be also results from the closing 'actionof-the mold noted at these grooves are positioned at parts compressing the several fabric plies substantially the central circumferential line is taken up by the surface areaof the core between the inner and outer peripheries of that isp'rovided by the grooves. thecore, and that the conjunction of the The. vulcanized'casing is removed from concave and convex areas are effected by the casing forming mold parts and stripped regular, but shorter curved areas, the imfrom the core in the usual manner. The vulportanoe of WhlOh will be later apparent. canized, but not inflated casing" is of the When building the casing upon the im-- same conformation as the surface area 'of the proved core the surface areafof the core becasing forming grooves in the companion tween the inner ed es 4, 4, of the grooves mold parts in which the casing has been vuland the inwardly directed flan e 5, is given canized, but by reason of the pressure ex he first ply fiferted upon the side walls of the casing by a covering of rubber cement; t of fabric or cord is placed upon the core an the inflated inner air tube, the casing when ,stitched, that is the ply is caused to conin service will assume the regular curved form to the surface area of the core, and the conformation as indicated by the broken edges are secured to the core by the adhesive lmes 10, 10, Fig.2.

observed by referring to the numerals 7, 7 the side walls of the casingto the regular Fig. 3, the fabric or cord'structure of cas-' curved surface conformation will effect a ing is not caused to conform to-the'surface compressing pressure in th'e direction of the It may be remarked that the, forcing of area of the grooves; the result is that when plane of the side walls of the casin the,

the casing is finally-completed by the casing result of which will effect a thickening of builder, there is space between the surface thev rubber compound covering the fabric face of the unvulcanized casing. and reflexing action of the casing when in The operation of the improved equipuse will be much better withstood b the ment when the casing isto be vulcanized is rubber compound projectin into the abric as fol1ows:'referring to the casing forming structure 0 the casing at t is most vulnermold parts, and to the annular casin formable point.

ing grooves 8, 8,. Fig. 1, it will be 0 served Having thus described my invention'withthat the circumferentially'directed'ribs 9, 9, out having attempted to set forth all'the that are off-set from the inner or mold sidesmodes of its use, I declare that whatI claim of the annular casing forming grooves 8, 8, and desire to secure by Letters Patent is aline with, and with the casing forming A casing mold comprising a airofcommold parts in closed position engage the p'lementary annular sections eac vhaving an grooves 3, 3, which are circumferentially diannular rib offset from its annular concave rected upon the surface of the, core. (It, molding surface, and an annular core eleis understood that proper clearance is proment having a molding surface normally exvided for the casing between the ribs and tending between the said complementary grooves when the mold parts are in closed annular sections, the said annular core ele-' position.)

By the means just described, the side walls of the casing are during the process of vulcanization caused to conform to the surface area of the annular grooves in the core, and the annular ribs off-set from the curved surface area of the casing forming grooves. Thus the surplus fabric or cordstock, that ment having grooves opposite the said an nular ribs.

In testimony whereof, I afiix my signaarea of the grooves 3,3, and the inner surstructure of the casing. Thus the flexing,

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