DE262993C - - Google Patents

Description

IMPERIAL

PATENT OFFICE.

PATENT LETTERING

- JVe 262993 CLASS 63 e. GROUP

HERMANN ZEUMER in KARLSRUHE i. B.

Patented in the German Empire on March 5, 1912.

The invention relates to a mold core, which is primarily used to produce seamless air tubes for pneumatic tires and consisting of a multi-layer spool consists of twine, which after the hose has been vulcanized like the usual balls of twine is dissolved in a known manner by pulling on the inner end.

It is known, even if for another

to ren purpose, one consisting of a single transverse layer, by means of helical winding a steel band created to use air-permeable core that extends over the whole Length of a finished hose section extends. The removal of this coiled Steel strap from a hole in the hose can be very difficult and ordinary only take place with damage to the hose material and cutting a slit, which can then be glued again in the usual way, with the generation a weak seam must be accepted.

It is also known to connect the butt ends of a circle to be joined together finished rubber hose to use a narrow roll, which is obtained by winding a canvas tape on a mandrel and after the joint ends have been glued by winding down from the inner end through an adjacent hose hole, at best through the valve hole can be pulled out.

In contrast to these known devices, the mold core according to the invention consists of a coil formed by winding a string or the like, which is not only in the longitudinal direction a very large number of layers of thread lying next to one another, but also several intersecting layers in the transverse direction Has layers, so that - with the help of a varnish impregnation - an in more resistant to the cylindrical or other shaped outer shape of the to be manufactured Rubber body exactly corresponding, the cavity of the end product filling the mold core is created, which in known Way by pulling on the inner end through the valve hole can.

In the drawing, as an example of the application of the mold core, is the generation of a Air tube for pneumatic tires illustrated.

In Fig. Ι and 2, the production is in a cross section and in a longitudinal view a mandrel shown.

The string b is, after it has been pulled through a vessel with glue, lacquer-like liquids o. by means of a winding device ο. Like. Wound on a mandrel a in several intersecting layers, so that a hose roll B of the required length and thickness is obtained. To

Claims (1)

the drying of the roll, the mandrel a is pulled out of the same and the roll is bent together to form a ring. The two butt ends B ¹ and B ² are now glued together (see Fig. 3), whereby the starting piece δ ¹ , directed towards the center of the circle, must be led out through the butt joint of the winding ring. The surface of the mold core produced in this way is painted over with plaster of paris or the like to remove unevenness. Now the rubber g is applied in lamellas that are wound around the core or can be placed on the same in the circumferential or other direction, possibly with the inclusion of intermediate layers of canvas left opening c the initial piece δ ^{1 of} the twine hangs through (see Fig. 4). Then the whole thing is placed in a metal mold in a known manner and brought into the vulcanizing furnace. After vulcanizing, pulling out all of the string through the Hole c by means of a reel or the like. Removed the winding from the finished tube and possibly immediately wound up into a new mandrel. 5 illustrates how, according to the invention, an air tube for pneumatic tires with two cavities separated from one another by an intermediate wall e can be produced with the aid of two mold cores of semicircular cross-section formed by twine rolls I and II. The figure shows that stage of the manufacturing process where the inner (not shown) of the two mold cores, I, has already been removed by pulling the string out of the finished tube. The starting ^{piece δ 1 of} the outer mold core, which has previously been passed through the hole d in the intermediate wall, then around the mold core I and together with the starting piece of this latter through the valve hole c, is now ready for winding on the reel or the like . The procedure in this embodiment is that between the two cores I and II, which are closed to form a ring, a rubber band with holes d forming the intermediate wall e is inserted, after which the actual hose g in the manner described above by applying rubber lamellae to the two-part Core is made. It is obvious that the mold core according to the invention for the production of hollow bodies of all kinds, different external designs and different material uses can find, for example, for the production of rubber balls, in which case the Molding core as a ball of thread, for the production of dolls bodies, with the molding core in several parts is formed and the like. A multi-part form core can not only, as shown in Fig. 5, in the transverse direction, but also be present with extensive wraps in the longitudinal direction. Pa τ ε ν τ - A ν s ρ r υ c 11: Mold core for the production of hollow rubber objects of all kinds, in particular of air tubes for pneumatic tires, characterized by its design as a multi-layer coil made of string. 1 sheet of drawings.