WO1987004569A1

WO1987004569A1 - Connecting device for simultaneously connecting a gas conduit and an electric cable

Info

Publication number: WO1987004569A1
Application number: PCT/SE1987/000029
Authority: WO
Inventors: Stig Lundbäck
Original assignee: Astra-Tech Aktiebolag
Priority date: 1986-01-27
Filing date: 1987-01-26
Publication date: 1987-07-30
Also published as: AU6932787A; SE450314B; JPS63502467A; DK442587A; SE8600359D0; DK442587D0

Abstract

Connecting device for simultaneously connecting a gas conduit and an electric cable to a device for emitting or receiving gas pressure and electrical signals. An outer tubular part (1) is arranged to be connected to the gas conduit (6) in such a way that the gas conduit communicates with the interior of the tubular part, which has at least one opening (11) in its periphery. An inner part (12) is arranged to be partly inserted into the tubular part in such a way that the parts are held to each other by means of cooperating engagement means (9, 15) located on said parts. The inner part (12) is provided with an axial wedge-shaped groove (25) in which an electric cable (26), having been passed through the gas conduit, is to be laid. In the connected condition the cable is clamped by the engagement means (9) of the outer part (1) in the wedge-shaped groove (25) in such a way that the groove, and thus the end of the inner part (12) which is inserted into the outer part (1), seals the corresponding end of the outer part (1).

Description

Connecting device for simultaneously connecting a gas conduit and an electric cable

The invention relates to a connecting device for simultaneously connecting a gas conduit and an electric cable to a device for emitting or receiving gas pressure and electrical signals, said gas conduit being tubular and said electric cable, being located within the gas conduit. The invention is especially intended for the case wherein a negative pressure (vacuum) is conducted in the gas conduit and is utilized to hold an electric contacting member, a signaltransmitter or similar by suction to a surface. For instance said member can be a contacting member of the kind disclosed in EP-A-84850320.7, which is an ECG-electrode held by suction. It can also for instance be an accelerometer for measuring vibration, or a microphone.

A problem is to achieve a common and simultaneous connection of the gas conduit and the electric cable to, for instance, a source of negative pressure or a signal receiver in a simple and reliable way. The object of the invention is to provide a connecting device which is simple and cheap to manufacture and can transmit gas pressure and electrical signals with a minimum of leakage and a satisfactory electric contact.

This object is realized in accordance with the invention by means of a connecting device having the characterizing features set forth in the characterizing clause of the main claim. Advantageous embodiments are defined in the depending claims.

The invention will now be described below with reference to the accompanying drawings, wherein Figure 1 illustrates the outer tubular part, longitudinal and partly sectioned, Figure 2 illustrates the inner part, also in longitudinal section, Figure 3 illustrating in the same way the two parts interconnected in use and Figure 4, 5 and 6 show sections according to the lines IV-IV, V-V and VI-VI in Figure 3.

The outer part shown in Figure 1, constituting the gas connecting part, consists of an elongated rotationally symmetrical tube 1, preferably made of plastics and having a smooth, essentially entirely cylindrical interior. The left end of the tube as seen in the drawing has a slight external taper 2, which passes into a cylindrical surface 3. The latter is provided with two annular flanges 4 and 5 at or close to the middle of the tube. The taper 2 serves as a guiding surface for a tubular member 6, for instance a hose of elastic material, which can be slipped on to the tube 1 (Figure 3) and then rests against the flange 4. An internal annular bead 7 on a tubular gripping member 8 can be snapped into the annular space between the flanges 4 and 5 (Figure 3). At the right end of the.tube, as seen in the drawing, the tube is terminated by an internal annular flange 9, having a bevel 10 facing the orifice of the tube. At least one aperture 11 is arranged in the tube wall between the flange 5 and the right end of the tube; in the illustrated embodiment two such apertures are situated diametrically opposed to each other.

The inner part 12, shown in Figure 2, forming the electric connecting part, is also a rotationally symmetrical but solid, elongated body and is also preferably made of plastics. Beginning at the left end, as seen in the drawing, this body has first a bevel 13 and then a section 14 with a diameter corresponding to the inner diameter of the tube 1. The section 14 changes into an annular groove 15, having an axial extent and a depth corresponding to the axial and radial extent of the flange 9 on the part 1.

An annular collar 16 is arranged adjacent the groove 15 and having a diameter equal to the diameter of the cylindrical surface 3 of the tube 1. After this follows a section 17 having a reduced diameter, a section 18 having an unreduced diameter which however is smaller than the diameter of the collar 16, a section 19 with a reduced diameter equal to the diameter of the section 17 and further a section 20 with a diameter equal to the diameter of section 18. Towards the right the part 12 terminates with a constricted section 21 changing into an approximately ball-shaped section 22.

The sections 17 and 19 are intended to receive contact rings 23, 24 (Figure 3) of a thickness such that the part 12 has an essentially constant diameter from the collar 16 to and including the section 20. With those contact rings mounted the inner part 12, from the collar 16 to and including the ball-shaped section 22, is equivalent to a male standard plug.

According to the invention a wedge-shaped groove 25, open towards the periphery, extends from the left end of the part 12 and having its apex at the periphery of the part, in the embodiment illustrated, in the transitional area between the sections 18 and 19. In the illustrated embodiment the groove 25 starts at the beginning of the bevel and ends on the diametrically opposite side of the part 12.

The electric cable 26, which to begin with is located in the gas hose 6, is passed through the tubular part 1 when using the connecting device according to the invention. The hose 6 is slipped on to the taper 2 and the adjacent cylindrical surface 3 of said tubular part 1 in such a way that the hose 6 seals against the surface 3 and rests on the flange 4 (Figure 3). In this embodiment the electrical cable 26 is a coaxial cable having an internal conductor 27, an insulation 28 for the conductor 27, a plaited screen 29 and an outer insulation 30. After a short length of the outer insulation 30 has been stripped, a short part of the screen 29 cut off and the insulation 28 removed from the end part of the conductor 27, the cable 26 is laid in the wedge-shaped groove 25 in the part 12 in such a way that the outer insulation 30 extends somewhat past the groove 15, the screen 29 extends over the section 17, the insulation 28 over the section 18 and finally so that the conductor 27 extends into the section 19.

After this the metal rings 23, 24 can be mounted over the sections 17 and 19 and clamped around these, so that electrical contact is achieved between the screen 29 and the ring 23 and between the conductor 27 and the ring 24. In the illustrated embodiment the rings 23, 24 are slit and the sections 17 and 19 on the part 12 are provided with grooves 31 and 32 into which the parts of the rings 23, 24 being situated on both sides of their respective slits are bent (Figures 3, 5 and 6). At this stage or before the electric connection, the parts 1 and 12 can be brought together, the bevels 10 and 13 will cooperate to guide the parts mutually and to achieve a necessary elastic widening of the part 1 as well as a certain compression of the part 12 made possible by the groove 25, necessary to allow the part 12 to be inserted into the part 1. The internal flange 9 of the part 1 then snaps into the groove 15 of the part 12 so that the parts are locked to each other. The depth of the groove 25 is such, in the vicinity of the flange 9, that the cable 26 is clamped between the flange and the groove. By these means a stress-relieving of the cable 26 is achieved as well as a seal due to the deformation of the elastic insulation 30.

The connecting device according to the invention is now ready for use, i.e. ready to be plugged into a special connection unit, including a female contact located farthest away in the direction of insertion, as well as a gas connection located outside the female contact and brought into communication with the apertures 11 and thereby with the interior of the g-as hose 6 in a way not shown here.

It is evident that the depth, inclination and length of the wedge-shaped groove 25 can be varied to suit different cable dimensions and different clamping requi ements. In the illustrated embodiment the groove is terminated in the transitional area between the sections 18 and 19 since the conductor 27 is thin, but the groove 25 can of course be continued into the section 19 for thick conductors. It is also possible to use the invention for a cable having only one or more than two conductors. It is also obvious that the width and bottom profile of the groove 25 are adapted for existing cable dimensions and cable shapes in order to achieve a satisfactory seal.

Claims

1. Connecting device for simultaneously connecting a gas conduit and an electric conducting means to a device for emitting or receiving gas pressure or electrical signals, said gas conduit being tubular and said electric conducting means being located within the gas conduit, characterized by:

an outer, essentially tubular part (1) which at one, first end is provided with connecting means (2) for the gas conduit (6), by which means the gas conduit can be connected to, and the electric conducting means (26) can be inserted into, the interior of the tubular part (1), said tubular part (1) being provided with at least one peripheral opening (11) in its tube wall at a distance from its other, second end;

an inner part (12) being provided at its periphery with an axially oriented groove (25) arranged to receive an electric conducting means (26) passed through the tubular part (1);

said outer (1) and said inner part (12) having cooperating engagement means (9, 15) whereby said parts are axially held together when a first end of the inner part is inserted into said second end of the outer part, the engagement means (9) of the outer part being adapted to achieve a clamping of said conducting means (26) laid in the axial groove (25) in order to hold said conducting means and at the same time seal said second end of the outer part (1).

2. Connecting device according to claim 1, characterized in that the axial groove (25) is wedge-shaped and widens in said first end of said inner part (1 ).

3. Connecting device according to claim 2, characterized in that said engagement means of the outer part (1) is an internal annular flange (9) and said engagement means of the inner part (12) is an external annular groove (15), the depth of said axial groove (25), in the vicinity of the internal flange (9), being less than the height of the conducting means (26) which is laid in the axial groove (25).

4. Connecting device according to any one of the preceding claims, characterized in that the inner part (12) is arranged to be provided with contact rings (23, 24), said axial groove (25) extending at least to the last ring (24), seen from said first end of said inner part (12).

5. Connecting device according to claim 4, characterized in that said inner part (12) is provided with one axial groove (31, 32) for each contact ring (23, 24), into which groove parts of the contact ring are bent in order to achieve a clamping of the contact ring around the inner part (12).