IL35293A - Connector fittings for tubes and hoses - Google Patents

Description

Connector fittings for tubes and hoses PLASSIM TECHNICAL PLASTICS WORKS FOR AGRICULTURE, INDUSTRY & BUILDING LTD.

The present invention relates to connector fittings tb for connecting tubes or hoses to each other/ machine parts, taps faucets or the like. The connector fitting according to the invention may also form an elbow or be branched, e.g.

T-shaped or star-shaped, in order to enable sudden changes of direction in pipe lines or the branching thereof.

There are known fittings of this kind which have' a male or female thread on or into which the tube or hose is screwed. It is, however, not possible to achieve in this way a satisfactory, tight adherence of the tube or hose to the fitting in particular where the tube or hose is of flexible material such as plastic or rubber.

In connection with fittings for rubber hoses it has furthermore been proposed to mount some rings on the hose which are formed with teeth directed towards the hose and which thereby offer a resistance to being pulled from the hose. These rings, which are in snug engagement with the hose throughout their axial leit&fch, are gripped by a cap nut whereby the end face of the hose end is forced against an annular abutment. That engagement under pressure constitutes the only sealed joint.

In addition to the fact that in such a construction the rings form loose parts which may easily be lost, a satisfactory seal is achieved only if the hose end coating forming the annular abutment is cut exactly at right angles to the longitudinal axis of the hose and is free of any unevennesses. This, however, is only rarely the case. Such connector fittings have proved entirely unsuitable for plastic hoses or tubes because in addition to the disadvantages described, the plastic material offers an excessive resistance to the mounting of the rings thereon. If the inside diameter of the teeth of the rings is only slightly larger than the outside diameter of the plastic tube or hose in order to facilitate the mounting of the rings thereon, a safe hold of tube or hose in the connector fitting is not ensured.

In an attempt to overcome these difficulties a further connector fitting for tubes or hoses has been proposed (see for example Israel Patent Specification No. 111.49). This fitting comprises at least one bore which is formed with inwardly directed annular ribs of- tooth-like cross section whose mouth is adapted to receive the end portion of a hose or tube, the tip diameter of the annular ribs decreasing from the mouth rearwards with the tip diameter of the innermost annular rib being less than the nominal diameter (outside diameter) of the tube or hose while the tip diameter of the outermost annular rib is suitably larger than the nominal diameter. In principal this fitting acts in a similar way as the ring-connector described hereinbefore, the improvement being that the assembly of individual rings is in this case replaced by a coherent, inwar serrated or indented tubular fitting.

The disadvantage inherent in both the above connector fittings is that the end portion of the tube or holes to be connected is gripped only from the outside without any counter-pressure from within. In other words, the connection between the fitting and the tube or hose is merely by exterior gripping as distinct from clamping. This, however, is a serious disadvantage when having regard to the flexible nature ofsahe^ tubes and hoses. further disadvantage is the fact that a the zone at which the tube or hose emerges from the connector is directly exposed to the surrounding atmosphere. Experience has shown that atmospheric influences with the result that at this zone the tube or hose tends to crack.

It is the object of the present invention to provide improved connector fittings for tubes or hoses.

In accordance with the invention there is provided a connector fitting for tubes or hoses comprising at least one clamping unit consisting of a core member and a guard member mountable thereon, the core member being adapted for the flow of liquid therethrough and comprising a tubular outwardly serrated adaptor with angular serrations whose diameter increases and whose angle decreases gradually from the tip towards the rear, said guard member comprising a tubular portion adapted for sliding on the tube or hose mounted on said adaptor, the interior of which portion is sub-divided into a rear, tapering zone adapted for a right fit on the hose mounted on the adaptor so as to clamp the hose between it and the adaptor, and a forward zone extending in the assembled state beyond the adaptor.

It is thus seen that in the connector fitting according to the invention the end portion of the tubular hose is clamped between a hollow core (the adaptor) inserted within the tube or hose, and an outer, matching member. In addition, due to the provision of the tubular extension of the guard member beyond the adaptor, that zone of the tube or hose which emerges from the clamping assembly and forms the transition between the clamped and undamped portion of the tube or hose and which, as explained before, is particularly sensitive to atmospheric influences, is protected.

Furthermore, by virtue of the fact that the angle of the serrations increases gradually from the adaptor tip towards the rear, it is ensured that the sharpest teeth are adjacent the rear The invention is illustrated, by way of example only, in the accompanying drawings in which: Pig. 1 is an exploded view of a connector fitting according to the invention adapted for the connection of one single tube or hose to a terminal, e.g. a metal pipe or tap; Pig. 2 is a section through the assembled fitting according to Fig. 1, showing the end portion of a hose clamped therein; and Pig. 3 is an exploded view of another embodiment of a connector fitting according to the invention adapted for the interconnection of two tubes or hoses.

The fitting illustrated in Pigs. 1 and 2 comprises a core member 1 having a body 2 with a throughgoing axial bore comprising a rearward, inwardly threaded broad section 3 adapted for screwing onto an outwardly threaded terminal, e.g. a metal pipe or a tap, which portion merges into a narrow tubular portion 4 extending through an adaptor 5. Adaptor 5 is outwardly serrated in that it comprises angular ribs 6, 7 and 8 each of which is in itself conically shaped as shown and whose outer diameter increases from the tip rearwards towards the body 2.

Additionally, as can be clearly seen in the drawings, the rib angles decrease from the tip to the rear, i.e. the angle of the rib 6 is largest whilst that of the rib 8 is leasi. In this way the three ribs form between them an imaginary outer conically shaped contour of the adaptor 5* Body 2 comprises a screw-threaded portion 9.

The guard member 10 of the connector fitting according to Pig. 1 comprises a body 11 having a throughgoing axial bore " The assembled connector fitting is shown in Pig. 2. As shown the guard member 10 is screwed onto the core 1.

It is further seen that a hose 16 is slid on adaptor 5· Ribs 6, 7 and 8 grip the hose from within thereby deforming its inner surface as shown and pressing the outer face of the hose against the conical portion 13 of the inner throughgoing bore of the guard member 10. In this way the end portion of hose 16 is firmly clamped and cannot be extracted. It is further aeen that themn-femped end portion of hose 16 extending beyond adaptor 5 is protected by the projecting portion 15 of the guard and in this way the sensitive interface portion of the hose is protected from atmospheric influences whereby the life time of the end portion of the hose is considerably prolonged.

The embodiment of a connector fitting according to the invention illustrated in Fig, 3 is adapted for the interconnection of two tubes or hoses. As shown it comprises a core member 20 having a body 21 with a throughgoing, axial bore 22 of even diameter throughout. In its medium zone body 21 comprises an annular flange 23 with a number of annularly arranged holes 24 adapted for the passage therethrough of tightening bo¾a 26 (only two of which are shown in the figure).

The core member 20 further comprises two identical terminal adaptors 27 each of which is of the same design as adaptor 5 of the embodiment of Figs. 1 and 2 ; they need, therefore, not be described in detail.

The fitting further comprises two identical guard members 28 which are again of practically the same design as guard member 10 of Figs. 1 and 2 with the sole difference that whic in the assembled state are in register with bores 24 of flange 23 of the core member 21 and with bores 30 of the other guard member. In this way the sets of bores 30 and 24 are adapted to receive between them the tightening bolts 26 by means of which the two guard members 28 and the core member 20 are tightened to each other to form one compact assembly.

The way in whiiSh a tube or hose is clamped between each guard member and the associated adaptor 27 is fully identical to that shown in ¾g. 2 and need therefore not be described again.

Obviously the invention is not confined to the two embodiments described hereinbefore by way of example only, and, as mentioned, the connector f itting in accordance wilnthe invention may also be in the form of an elbow, T-shaped, star-shaped and the like and quite generally be ads¾pted to any fluid flow system in which tubes, hoses or pipes have to be connected to a stationary terminal or interconnected in a mutually aligned or angular relationship.

When a connector fitting according to the invention comprises several clamping units it may in addition comprise means for connection to a fixed terminal.

Furthermore, although the connector fitting according to the invention are particularly suitable for the connection of flexible tubes or hoses they are not confined thereto and may also be used for the connection of non-flexible tubes or pipes or hoses such as made, for example, of hard plastic material , hard rubber, various metals,, provided that such materials are not brittle. 35293/2

Claims (5)

1. Δ connector fitting for tubes or hoses comprising at least one clamping unit consisting a core member and a guard member mountable thereon, the core member being adapted for the flow of liquid therethrough and comprising a tubular outwardly serrated adaptor with angular serrations whose diameter increases and whose angle decreases gradually from the tip towards the rear, said guard member comprising a tubular portion adapted for sliding on the tube or hose mounted on said adaptor, the interior of which portion is sub-divided into a rear, tapering zone adapted for a tight fit on the hose mounted on the adaptor so as to clamp the hose between it and the adaptor, and a forward zone extending in the assembled state beyond the adaptor.

2. · A connector fitting according to Claim 1, being adapted for connection of a tube or hose to a fixed terminal and comprising one single clamping unit.

3. A connector fitting according to Claim 1, serving for interconnecting two or more tubes or hoses comprising at least two clamping units.

4. A connector fitting according to Claim 3, comprising in addition means for connection to a fixed terminal.

5. Connector fittings, substantiall as described herein. For the Applicants REIMHOLD COM AMD PARTNERS