DE2400892A1 - Reinforced elastomer hose for automatic washing machine - by placing reinforcement upon mandrel, applying elastomer cover, and vulcanising cover while applying pressure drop - Google Patents

Abstract

Reinforced elastomer hose esp. an outlet hose for an automatic washing machine, is produced by (a) placing the reinforcement upon a mandrel, (b) placing an uncured elastomer cover over the outside of the reinforcement, and (c) vulcanising the cover while a pressure drop exists over the cover from its outside to its inside. The process is cheap and a lining is not required. The smooth inner surface facilitating flow, and prevents blockages caused by fluff and other material.

Description

Reinforced elastomeric hose and method of making it The invention relates to reinforced hoses and a method for their manufacture and particularly relates to outlet hoses for automatic washing machines.

An automatic washing machine is in At intervals water either directly to a flexible hose Drainage pipe or delivered to a sink. When the hose clogged or is kinked, there is an overpressure of water within it, with the result the hose can come loose, causing flooding or malfunction caused by the washing machine.

It is therefore desirable that outlet hoses have smooth internal surfaces have, on the one hand to reduce the flow resistance and on the other hand to prevent lint or other material collects in the hose and clogs it. It is also desirable that such hoses be reinforced to prevent them from being crushed and to withstand kinking.

One known method of making reinforced tubing includes the installation of a reinforcement over a hose lining with a smooth bore, which is mounted on a mandrel, whereupon an uncured rubber sleeve attached to the outside of the reinforcement, the rubber then in place hardened and finally the mandrel is removed. There are several possible # embodiments a reinforcement, such as a helical wire, over the liner wrapped or pushed, or a braided sleeve made of synthetic fiber.

It is also known that a pressure difference between the inside and the outside of the hose to act.

The invention is based on the object of a simpler and therefore to provide a cheaper method of making a reinforced hose and to make a hose, where no lining is required is.

This object is achieved according to the invention by a method of manufacturing a reinforced, elastomeric hose, detached, which is characterized by that the reinforcement is applied directly to a mandrel and an uncured, Elastomer cover attached to the outside of the reinforcement and vulcanized or is cured while a pressure drop across the coating from its outside on its inside. A preferred embodiment is characterized in that the mandrel is hollow and interrupted in this way by a large number of holes is that a relatively low pressure within the mandrel is uniform across the inner surface of the coating comes into play. As a reinforcement can be useful a screw-like winding, preferably made of metal, can be used.

The pressure drop across the cover causes it to move during of curing around the reinforcement and against the mandrel, thereby forming the hose receives a smooth inner surface and embeds the reinforcement. Preferably there is play between the reinforcement and the mandrel so that after hardening the coating completely embeds the reinforcement. However, the reinforcement can also peek through after hardening and part of the inner surface of the hose form over its entire circumference or part of it.

The ends of the cover can be sealed with the mandrel or over the ends of which are closed to the inside of the coating to isolate against the pressure during vulcanization or curing. At one or the coating can be left outside the vulcanization chamber at both ends, in which case a negative pressure or vacuum within the coating to act on can be brought.

The Ertadung also creates a reinforced hose in which the Reinforcement embedded in a single layer of rubber or an elastomer is.

The coating can consist of natural or synthetic rubber.

The mandrel can be straight or according to the desired shape of the hose be designed or curved.

The reinforcement can be of any suitable type consist of any material that can be used by the curing or. Vulcanization process is not being affected.

The invention is based on an exemplary embodiment below the drawing explained in more detail, namely: Fig. 1 is a perspective view of a mandrel with a reinforcement during the application of an uncured X-rubber sleeve over the reinforcement; Fig. 2 is a side view of the reinforcement and the Mandrel attached to the rubber sleeve in preparation for the vulcanization process is locked; and Figure 3 is a perspective view of a piece of the finished product Hose.

According to the drawing, the reinforcement consists of a metal helix 2, which has been pushed or wrapped over a mandrel 1, which is of a multitude is pierced by small holes 4.

The holes in the mandrel 1 should be small enough to prevent that the rubber penetrates under the action of pressure, but at the same time large enough not to get clogged by the rubber. A preferred size range the hole diameter is between about 1/64 and 1/32 of an inch (0.4-0.8 mm).

The size of the reinforcement 2 is such that it loosely over the Mandrel 1 fits. An extruded, uncured rubber coating 3 is then attached as a sleeve over the reinforcement 2, so that it consists of the entirety Thorn and reinforcement covers. If the cover is not pushed over the reinforcement can be stretched when it is attached, for example by inflating it.

The coating 3 is then at its ends 5 and 6 over the ends of the Mandrel 1 closed, for example by clips or by tying off. The whole will then placed in a vulcanizing device and vulcanized under steam pressure.

The pressure within the coating 3 remains in the range of atmospheric Pressure with only a slight increase due to the increased temperature and the small volume reduction during curing. Nevertheless there is a Pressure drop from the outside to the inside across the cover, with the result that the rubber cover 3 the metal coil 2 and in contact with the mandrel 1 occurs, the rubber then hardening to form a reinforced hose 7 which the mandrel 1 can be pulled out.

The hose obtained in this way can, if desired, be cut into shorter pieces be cut up.

In cases where a U-shaped bend is required to get well over To fit a sink or to a drainpipe, the reinforcement can be added in front of the End the bend and add a separate piece of extruded rubber, by shaping it around the U-shaped bend made on the mandrel. This separate extrusion may be of a harder composition, so that after curing it forms a solid lining for the softer composition, which is used for the entire hose.

This process results in a flexible reinforced hose with a smoother inner surface, which is also resistant to moving together and buckling is without (at least in most balls) a lining is required, which results in a considerable simplification of production and saves costs will.

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Claims (6)

A n s'p r ü c h e 1 \ Method of making a reinforced elastomer Hose, d u r g e k e n n n e i c h n e t that the reinforcement (2) applied directly to a mandrel (1) and an uncured elastomer Cover (3) attached to the outside of the reinforcement and vulcanized or is cured while a pressure drop across the coating from its outside on its inside. 2. The method according to claim 1, d a d u r c h g e k e n n --z ei c h n e t that the mandrel (1) is hollow and interrupted in this way by a multitude of holes (4) is that a relatively low pressure within the mandrel is uniform across the inner surface of the coating (3) comes into play. 3. The method according to claim 1 or 2, d a d u r c h g e k e ii n z It is true that the reinforcement (2) is a helical reinforcement. 4. The method according to any one of the preceding claims, characterized thereby I do not know that there is play between the reinforcement (2) and your thorn (1), so that the coating completely encloses the reinforcement after curing. 5. Manufactured according to the method according to one of the preceding claims, reinforced, elastomeric hose. 6. Reinforced, elastomeric hose according to claim 5, d a -d u r c it is noted that the reinforcement (2) is divided into a single layer (3) made of an: elastomer is embedded, which forms the wall of the hose.