Patent Grant
9318843
This application claims priority to pending European patent application EP 13177114.9 filed Jul. 18, 2013, which is incorporated by reference in its entirety.
1. Field of the Invention
The invention relates to a coaxial plug-and-socket connector for radio frequency (RF) electrical signals, comprising a plug part and a socket part and further comprising a coupling nut for fixing the parts together.
2. Description of Relevant Art
To achieve a secure and reliable connection between the parts of coaxial connectors, coupling nuts are frequently used. Such a coupling nut is disclosed in U.S. Pat. No. 8,235,741 B2. The nut has an inner thread interfacing with an outer thread of the other connector part. Preferably, the nut is tightened by manually or by using a torque wrench to avoid excessive torque, and therefore excessive force to the connector and its contact system. If the nut is tightened with excessive torque, it may even be damaged.
An electric plug-in connector with a coupling nut is disclosed in U.S. Pat. No. 8,408,938 B2. The coupling nut is rotatable against the outer conductor of the plug connector. It has an inner thread interfacing with an outer thread of a socket part. To avoid tightening with an excessive torque, even without a torque wrench, a component is provided which is shorn off in the case of excessive torque. The disadvantage is that the connection can no more be reopened and reused.
US 2007/0145744 discloses a multi-pole connector which uses a stop ring between a union nut and a mating connector to prevent damage of a sealing element.
When tightening a coupling nut of an RF connector, there may be significant internal friction in the connector, which also causes the attached cable to rotate or at least may prevent a later rotation of the cable, if necessary. This may impose a significant mechanical tension on the cable.
The embodiments are based on the object of providing a coaxial connector with a coupling nut, which allows a connected cable to rotate slightly, even if the coupling nut is tightened with a high torque, and which can easily be assembled and can be manufactured at comparatively low manufacturing costs.
Solutions of the problem are described in the independent claims. The dependent claims relate to further improvements of the invention.
In a first embodiment, an electrical connector, preferably a coaxial RF connector comprises a coupling nut. The electrical connector may be either a plug connector, a socket connector, or a hermaphroditic connector, although a plug connector is preferred. The connector preferably has a center axis which is defined by a center conductor of a coaxial system. The electrical connector may be connected to a mating connector. Such a mating connector may be a socket connector, a plug connector or a hermaphroditic connector; although a socket connector is preferred. The coupling nut has an inner thread, which interfaces, with an outer thread at the mating connector. It is preferred, if a plug connector has a coupling nut with an inner thread interfacing with an outer thread of a socket connector. The connector is locked to a mating connector by the coupling nut which holds the connector and the mating connector in close proximity. By rotating the locking nut, the connector may be pressed against the mating connector in a direction parallel to the center axis, further referred to an axial direction.
As shown in the prior art, a protrusion at the coupling nut directly interfaces with a corresponding protrusion at the outer conductor or a part of the housing of the connector. This causes a direct coupling of force from the coupling nut into the connector.
To allow at least a minor rotation around the center axis or even a full rotation of the connector and therefore of a cable attached to the connector, the mating connector may not be pressed hardly against the connector by the coupling nut, so that friction between these parts does not prevent rotation. It is preferred, if there is a minor gap in axial direction between the connector and the mating connector which allows rotation. Preferably, there is no seal in axial direction between the connector and a mating connector, as this would introduce an additional unwanted friction. Preferably, there is only a radial seal pressing in radial direction between the connector and a mating connector. Whereas an axial seal may easily slide off the connector and may get lost, a radial oriented seal may be held within a groove and cannot get lost. Furthermore, the grove provides a precise guidance of the seal.
According to the preferred embodiment, a locking ring 130 is provided between the coupling nut 120 and the connector 110. The locking ring is a separate part and preferably is made of metal, although it may also be made of a plastic or similar material. Preferably, it has a Z-shaped cross section. It has a cylindrical body with an inner protrusion at the inner side of the cylinder and an outer protrusion at the outer side of the cylinder. The inner protrusion is forming a first locking ring contact surface 131 which may interface with a first protrusion contact surface 113 formed by a protrusion 116 at the connector 110, preferably at the outer conductor of a coaxial connector. The outer protrusion is forming a second locking ring contact surface 132, which may interface with a coupling nut contact surface 121 of the coupling nut. Preferably, the first locking ring contact surface 131 and the second locking ring contact surface 132 face radially into opposite directions. Finally, the locking ring has a third locking ring contact surface 133, which may interface with the mating connector at a first mating connector contact surface 211. Preferably, the first locking ring contact surface 131 and the third locking ring contact surface 133 are oriented axially into the same direction. For interfacing with the locking ring 130, the connector has a protrusion 116, which has a first protrusion contact surface 113, and in axial direction on the opposite side of the protrusion 116 a second protrusion contact surface 117, which may contact the mating connector 200 at a second mating connector contact surface 212. This limits the movement of the connector between the locking ring and the mating connector. The distance between the first locking ring contact surface 131 and the second mating connector contact surface 212 is larger than the width of the protrusion 116 of the connector. The first mating connector contact surface 211 may be the same as the second mating connector contact surface 211. Preferably, the distance between the first locking ring contact surface 131 and the third locking ring contact surface 133 is larger than the protrusion of the connector. If the outer protrusion of the locking ring is close to the third locking ring contact surface 133, then the length of the locking nut can be reduced over a locking nut interfacing with the first protrusion contact surface 113 of the connector. Therefore, the connector can be built smaller.
The function is as follows: When the coupling nut 120 is tightened, the coupling nut contact surface 121 is moved towards the mating connector 200. As it stays in contact with the second locking ring contact surface 132, it moves the locking ring into the same direction. This further causes the connector 100 to move, because the first locking ring contact surface 131 interfaces with the first protrusion contact surface 113 of the protrusion 116. When the coupling nut 120 is tightened, its movement is stopped, as the coupling nut contact surface 121, which is in contact with the second locking ring contact surface 132 of the locking ring 130, presses the locking ring 130 with its third locking ring contact surface 133 against the first mating connector contact surface 211. As the coupling nut cannot further move into the direction of the mating connector, it can no more be rotated, and the connector is locked. Because, as described before, the distance of the first locking ring contact surface 131 to the second mating connector contact surface 212 is larger than the width 114 of the protrusion 116, the protrusion and therefore the connector 100 is not rigidly pressed against the mating connector. Therefore it may rotate at least slightly. To allow rotation, it is preferred, if there is at least small gap between the components of the connector and the mating connector, when the coupling nut is tightened.
Summarizing, the coupling nut is not coupled directly to the connector. Instead it is coupled by means of the locking ring, which holds the connector against the mating connector allowing some movement of the connector against the mating connector.
It may be sufficient to make the difference of distances which results in a gap between the connector and the mating connector, significantly lower than 1 mm, preferably less than 0.1 mm, and most preferably less than 0.01 mm.
To simplify assembly of the connector, it is preferred if the locking ring 130 has a groove or gap 112 which allows compression of the locking ring, reducing its diameter and easy insertion into the coupling nut 120. In a first assembly step, the locking ring 130 is pushed over the protrusion 116 of the connector 100 into a groove 112 and is compressed so that its outer diameter is less than the inner diameter of the coupling nut. Then, the coupling nut 120 may be slid over the connector and over the locking ring. The locking ring may also be automatically compressed by sliding the coupling nut over a ramp-shaped surface of the locking ring. When the coupling nut is in its final position with respect to the locking ring, the locking ring may be released or it extends by its spring force to fit into the coupling nut. If there is a circular groove in the nut, the groove comprising the coupling nut contact surface 121, then the sidewalls may hold the outer protrusion of the locking ring and therefore hold the locking ring at the nut. This prevents loosing of the locking ring, when the connector is open.
A further embodiment comprises a RF connector pair comprising a RF connector (100) and a mating connector (200). Both connectors are designed to fit to each other.
In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
In
Actually, this figure shows a pair of connectors (100, 200) in a mated state, when the third locking ring contact surface (133) contacts the first mating connector contact surface (211). Here, the first mating connector contact surface (211) and the second mating connector contact surface (212) are in the same plane, although they may be in different planes.
In
In
It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide RF connectors for coupling radio frequency signals. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13177114 | Jul 2013 | EP | regional |
| Number | Name | Date | Kind |
|---|---|---|---|
| 6358077 | Young | Mar 2002 | B1 |
| 6464527 | Volpe et al. | Oct 2002 | B2 |
| 7077700 | Henningsen | Jul 2006 | B2 |
| 8235741 | Schulze et al. | Aug 2012 | B2 |
| 8408938 | Proeckl | Apr 2013 | B2 |
| 20070145744 | Mehnert et al. | Jun 2007 | A1 |
| 20080302565 | Gaidosch | Dec 2008 | A1 |
| Number | Date | Country |
|---|---|---|
| 101 807 765 | Aug 2010 | CN |
| 103 53 886 | Feb 2005 | DE |
| Number | Date | Country | |
|---|---|---|---|
| 20150024618 A1 | Jan 2015 | US |
