The present invention relates to a connector for a hy¬ draulic pressure hose. The connector comprises a body, provided with a first sleeve member to be fitted inside the end of a hydraulic pressure hose, and a connecting member which preferably includes a fixing means for a working tool and a fastening means, such as a threaded portion, for fastening the connector to a hydraulic system, as well as a second sleeve member to be fitted outside the end of a hydraulic pressure hose face to face with the first sleeve member, said first and sec¬ ond sleeve members b,ing adapted, upon mounting the connector on a hydraulic pressure hose, to squeeze to- eards each other and to clamp the end of a hydraulic pressure hose therebetween.

This type of connectors are prior known and particular¬ ly used in hydraulics. The modern hydraulic systems not only include more and more actuators but also a lot of controls. Electrical control, e.g. in terms of valves, pumps and hydraulic motors, is highly complicat¬ ed and susceptible to trouble in modern systems.

An object of this invention is to introduce such a con¬ nector for a hydraulic pressure hose, which is to a sub- stantial degree capable of eliminating the present draw¬ backs and, thus, of improving the prior art. In order to achieve this object, a connector of the invention is primarily characterized in that at least a part of at least one of the sleeve members of the connector is electrically insulated from the body.

The above solution is capable of providing a simple- design hydraulic pressure hose connector provided at

the same time with one or more possibilities for elec¬ tric connection providing that the question is about a hydraulic pressure hose which is fitted with one or more conductors with which one or more sleeve sections included in the sleeve member are in electrical contact when the connector is mounted on the end of a hydraulic pressure hose. Thus, the hydraulic pressure hose can be employed, on the one hand, as a hydraulic medium carrier hose and, on the other hand, e.g. for the con- trol of actuators in the transmission of electric mes¬ sages.

The invention relates also to a hydraulic pressure hose for use in association with the connector, the substan- tial characterizing features of said hose being set forth in the characterizing section of the independent claim directed to a hydraulic pressure hose.

The invention will now be described in more detail in the following specification with reference made to an exemplary embodiment shown in the accompanying draw¬ ings. In the drawings

fig. 1 shows a perspective view of a connector of the invention mounted on a hydraulic pressure hose,

fig. 2 shows a connector in a longitudinal section prior to mounting, and

fig. 3 shows a connector mounted on the end of a hydrau¬ lic pressure hose also in a longitudinal section.

Rererring particularly to fig. 1, a connector 1 of the invention is mounted on a hydraulic pressure hose 2. The outer surface of connector 1 is fitted with an elec-

trie coupling means 3 with an electric wire 4 extending therefrom. The electric coupling means 3 is a shaped piece assembled with a screw 5 to a ring shape. Screw 5 is located between brackets 6 in the electric cou- pling piece.

Fig. 2, in particular, illustrates the main components of a connector of the invention. Connector 1 has a body 7 which includes as its main components a first sleeve member 8 and a connecting member 11. The first sleeve member 8 is fitted inside a hydraulic pressure hose when installing the connector on a hydraulic press¬ ure hose. The body 7 further includes a fastening means 10 for a second sleeve member 9, said fastening means extending from the end of a hydraulic pressure hose as an integral part of sleeve member 8. The fastening means 10 is followed by connecting member 11 for said body 7, said connecting member including a fixing or gripping means 12 for a tool, e.g. a nut member intend- ed for an adjustable wrench, as well as a fastening means as an extension thereof, such as a threaded por¬ tion 13 for coupling the connector to a hydraulic sys¬ tem.

The second sleeve member 9, in turn, includes a first sleeve section 14, a second sleeve section 14, and an insulation member 16 therebetween. The above-mentioned components 14-16 are mounted on the outside of the machined end of a hydraulic pressure hose surrounding said end of hydraulic pressure hose 2.

In the illustrated embodiment, the body 7 and the sec¬ ond sleeve member 9 are coupled together by using on the one hand a fastening means 10, provided with an outwardly-directed jutting annular collar 17 extending

from the end of hydraulic pressure hose 2 mounted on top of sleeve member 8 and'extending into said sleeve member as well as with an annular groove 18 position¬ ed between said annular collar 17 and gripping means 12. Accordingly, the first sleeve section 14 includes as counter-fastening means an internal groove 19 in line with annular collar 17 and an inwardly-directed annular collar 20 in line with annular groove 18. The components of said second sleeve member 9-are di- mensioned in a manner that, when machined at its end for mounting, the hydraulic pressure hose can be in¬ serted in a cylindrical annular space formed by the outer surface of first sleeve member 8 and the inner surface of second sleeve member 9. The sleeve sections 14, 15 of said second sleeve member 9 carry on their internal surface cross-sectionally preferably triangu¬ lar , inwardly-directed annular collars 21 at fixed spacings, in this case two in each sleeve section 14, 15. On the other hand, the first sleeve member 8 is provided on its external surface and also at fixed spacings with a plurality (four) of grooves 22 which are linked with each other through the intermediary of equidiameter necks 23. The external surface of necks 23 is parallel to the centre axis 24 of first sleeve member 8.

Between first and second sleeve sections 14, 15 is fitted an insulation member 16. The insulation mem¬ ber 16 is fixed in annular grooves 27 formed on the opposing frontal surfaces 25, 26 of sleeve sections 14, 15 (in the present embodiment one annular groove 27 in each frontal surface 25, 26) , said grooves being sub¬ stantially of equal size and shape. The insulation member 16 is annular in configuration and includes annular collars 28, extending in both directions from

its radial side faces and set in said annular grooves

27 made in first and second sleeve sections 14, 15.

As particularly shown in fig. 2, the insulation member 16, which is preferably made of ebonite material and thus has a resilient structure, is designed in a manner that the cross-sectional area of annular collars 28 in a rest condition (prior to the mounting of a connector) is smaller than that of annular grooves 27, whereby the resilient insulation member 16 yields as said second sleeve member 9 is pressed against the external surface of hydraulic pressure hose 2. Thus, the annular collars

28 of insulation member 16 fill the annular grooves, as shown in fig. 3. The annular grooves _ '. . can preferably be designed as a dovetail shape expanding towards the bottom.

In the embodiment shown in figs. 2 and 3, a hydraulic pressure hose 2 of the invention includes as its inner¬ most component an inner rubber layer 29. Outside that is a first conductor layer 30. Outside the first conductor layer 30 is in turn an intermediate insulation layer 31 with a second conductor layer 32 on its outer surface. The outermost component in a hydraulic pressure hose is an outer layer 33. The materials for layers 29, 31 and 33 can be e.g. rubber or ebonite. As illustrated in figs. 2 and 3, the hydraulic pressure hose has its end machined in a manner that, at said first sleeve section 14, the material is removed up to intermediate insula¬ tion layer 31 and, at said second sleeve section 15, there is no material removed at all or material is re¬ moved up to second conductor layer 32.

Starting from the situation shown in fig. 2 and effect¬ ing a conventional press clamping of the hydraulic press¬ ure hose connector e.g. by means of a device disclosed ^'

in GB Patent 2 003 776, which device, especially its jaw assembly, can be subjected to necessary structural modifications required particularly by the insulation member, the result will be a situation as shown in fig. 3, wherein the first layer 29 of a hydraulic pressure hose is pressed in grooves 22 of the first sleeve mem¬ ber and the annular collars 21 of first sleeve section 14 are partially penetrated into said first layer 29 and said annular collars 21 as well as the entire es- sential portion of sleeve section 14 between annular collars 21 are in good electrical contact with the first conductor layer 30 of a hydraulic pressure hose.

The inner surfaces in proximity of the first sleeve sec- tion 14 and the insulation member 16 of second sleeve section 15, as well as the entire insulation member 16, are in connection with the central intermediate insula¬ tion layer 31 of a hydraulic pressure hose. On the ot¬ her hand, said second sleeve section 15, particularly at annular collars 21, has squeezed into contact with the second conductor layer 32 of hydraulic pressure hose 2. The outer surface of second sleeve member 9 is possibly after the pressing still subjected to insula¬ tion coating, e.g. by the application of insulating rubber 34.

An electric coupling means 3, made of an insulating material as for its body 3a, is coupled, on the one hand, with an annular bracket 35 associated with first sleeve section 14 and extending from its outer surface and, on the other hand, with a complementary-shaped annular bracket 36 associated with second sleeve sec¬ tion 15, said brackets being located on either side of insulation member 16. Said annular brackets 35 and 36 are adapted to receive complementary-shaped grooves 37

and 38 extending in said electric coupling means 3 to its inner surface 40 clamping to the outer surface of one sleeve section 14, said grooves being provided with coupling means 37a and 38a for electrical wires 4a and 4b. The inner surface 40 of electric coupling means 3 is also provided with an outwardly-directed groove 39 for a portion 16a included in insulation member 16 and extending from the outer surface of the sleeve member 9 of insulation member 16.

On the basis of the above it is obvious for a skilled person that a connector of the invention can be con¬ siderably varied within the scope of the basic inventive conception. It is obvious that, first of all, between body 7 and first sleeve section 14, e.g. between com¬ ponents 17, 18 and 19, 20, can be fitted an electrical insulation (detail 39 in fig. 2) , whereby said body 7, for example, can be used in the grounding of a hydraulic system. On the other hand, it is clear that the de- scribed radially-directed spacing of second sleeve mem¬ ber 9 can be replaced with a spacing of zones between different electric circuits in the circumferential di¬ rection of a hydraulic pressure hose, whereby the in¬ sulation member extends in the longitudinal direction of the sleeve member instead of and/or in addition to the radially-directed insulation me:_ιber 16 shown in figs. 2 and 3. It is further obvious that the first sleeve member 8 can also be divided into sleeve sections which extend into various layers.