Protective cap with internal retaining device

Abstract

Arrangement for a retaining element (40) and protective cap (3), which can be screwed onto a connector housing (1) with connectors (20) arranged therein via a thread (g) onto the mating thread (c) and in the screwed-on state the retaining element (40) is completely enclosed in the protected area, characterized in that the protective cap is held captive on the connector housing.

Description

[0001] The invention relates to the connection of a protective cap to a housing which accommodates a connector. This connector, consisting of contacts for signal transmission and a contact carrier, is placed in this connector housing, which has a thread for the mechanical connection of a protective cap that has a mating thread and can thus be mechanically screwed onto this connector housing.

[0002] A protective cap of this type is required to protect connectors, as they are often exposed to dust and moisture in their operating environment. These sometimes harsh environmental conditions can easily lead to contact contamination, preventing reliable signal transmission. The risk of losing this protective cap can be largely eliminated with a suitable retaining device attached to the typically stationary connector housing. The assembly, consisting of the connector housing, connector, and retaining device, is installed in a standard mounting hole, creating a feedthrough for data, signals, or power electronics. The protective cap mounted on the connector housing can provide a seal against media, foreign objects, or electromagnetic radiation. State of the art

[0003] From DE 20 2011 050 067 U1, a cap fastening using a retaining device is known, wherein in the cap fastening a cap is attached to the connector by means of a retaining band. The retaining band is rotatably attached at one end to the connector and at the other end to a pin, the pin being mounted centrally on the cap.

[0004] Furthermore, arrangements are known in which the cap is attached to the connector by means of a chain or a rope.

[0005] A disadvantage of previous solutions is that the retaining element for the protective cap is located outside the area protected by the cap. This can lead to the retaining band being torn off or damaged. Furthermore, the rotating attachment to the cap's pin often provides insufficient protection against bacterial growth. Therefore, the use of this type of secured protective cap in food processing and chemical plants is often limited. Task

[0006] The invention is therefore based on the objective of placing the holding means within the area enclosed by the mounted protective cap.

[0007] This problem is solved by having the connector housing have an opening for the retaining element in addition to the opening for the connector itself. The retaining element can be placed inside the area enclosed by the protective cap during connector assembly. The bore for the pin on the protective cap is also located within this area, and thus protected by the cap. With the protective cap in place, the retaining element is therefore completely enclosed and, like the connector, protected from external influences.

[0008] Advantageous embodiments of the invention are specified in the dependent claims. Some of these can be combined.

[0009] The invention preferably relates to a protective cap for electrical connectors for data transmission. These include, for example, USB, RJ or HDMI connectors as well as standard industrial circular connectors.

[0010] The connector housing has a thread that mechanically connects the protective cap. In a preferred embodiment, the thread of the connector housing is an external thread and the thread of the protective cap is an internal thread.

[0011] According to the invention, a retaining element is provided for the captive attachment of the protective cap to the connector housing. In a first embodiment, the retaining element is designed as a molded plastic part. After installation in the connector housing, this part is secured within the housing and is rotatably connected to a pin on the protective cap. The bore for this pin is preferably located in the center of the threaded axis of rotation. After the connector is installed in the housing, it is typically filled with a casting resin. This casting process is suitable for securing the retaining element within the connector housing.

[0012] In a preferred embodiment, axial movement of the retaining element within the connector housing is provided. This allows the retaining element to be inserted into the housing during protective cap installation, requiring less installation space between the connector housing and the protective cap. This makes it possible to position the protective cap closer to the connector at its end, resulting in a shorter assembly and preventing the retaining element from being pinched between the internal and external threads.

[0013] This axial movement of the retaining element can be further supported by another design. In this design, a spring element is mounted between the end stop on the retaining element and the connector housing. When the protective cap is unscrewed, the spring element is tensioned. When the protective cap is screwed back on, the spring force assists the retraction movement of the retaining element into the connector housing, making it less susceptible to kinking.

[0014] In a further preferred embodiment, the retaining element is designed as a cable, preferably made of steel. The round cross-section of the cable allows for a cost-effective bore as the housing opening while simultaneously providing a high axial holding force compared to molded plastic parts. To achieve axial securing, an end stop, hereinafter referred to as the cable stop, is optionally pressed or overmolded onto the steel cable. The cable stop can be designed such that the retaining element is rotatably mounted in the housing. Mounting to the protective cap by means of a pin is facilitated by a terminal pressed onto the cable, which rotatably receives the pin.

[0015] In a further preferred embodiment, the protective cap is made in multiple parts. The retaining element, designed as a cable, has a cable stop at both ends. A corresponding molded part can be formed at this point. The retaining element is inserted into the multi-part protective cap, the assembled protective cap providing a positive fit against the end stop on at least one surface. The retaining element is rotatably mounted, preventing axial withdrawal from the protective cap.

[0016] Another design uses an elastic retaining element, eliminating the need for axial movement to the connector housing and a rotatable bearing. This elasticity allows for a shorter design on the protective cap without requiring additional space within the connector housing.

[0017] Another design involves an alternative method of attaching the protective cap to the connector housing. Instead of using the threads of the two components, a different connection technology is employed. These are typically precision fits or bayonet connectors.

[0018] The advantages achieved with the invention lie particularly in the fact that the retaining element and the connector are protected from forces and environmental influences by the protective cap. This also enables a design that meets higher standards with regard to hygiene or mechanical requirements, since, in the closed state, no further gaps, bearing elements, or retaining elements are located outside the space enclosed by the protective cap. The choice of material for the retaining element can therefore be made less dependent on external influences. In addition, the space already provided for in the connector housing can be used to further shorten the captive protective cap assembly. Example of implementation

[0019] A combination of the above-mentioned embodiments of the invention is shown in the drawing and is explained in more detail below. The drawing shows: Fig. 1 Several plug contacts (22) are mounted in a plug housing (21) to form a connector (20), which is oriented in a front-facing bore (a) in the connector housing (1). A retaining element can be passed through the second front-facing bore (b) in the connector housing. The connector housing (1) also has two external threads, one (c) being used for attaching a protective cap and one (d) being used for mounting in a wall using a nut. Fig. 2 a connector (20) in the connector housing (1) with a protective cap (3) which is secured in the bore (b) of the connector housing (1) by a rope-like retaining element (41) in the open state, Fig. 3 a pin connector in the connector housing (1) with protective cap (3) in the closed state in which the protective cap with the internal thread (g) is screwed onto the external thread (c), Fig. Figure 4 shows a sectional view of a connector (20) in the connector housing (1) with protective cap (3) in the open state, as well as an embodiment of the retaining element (40) with a cable stop (42) mounted in the connector housing (1) and a terminal (43) mounted on the protective cap (3), which is rotatably mounted (f) on the protective cap (3) by means of pins (5). The retaining element (40) can be inserted into the free space (e) of the connector housing (1) when the protective cap (3) is to be screwed on. Fig. Figure 5 shows a sectional view of a two-part protective cap (30) in which the outer part of the protective cap (31) rotatably receives (f) a rope stop (44) for securing the holding device (41) via the bore (h). The inner part of the protective cap (32) prevents this rope stop from being pulled out. Fig.Figure 7 shows a sectional view of a connector housing (1) with a mounted connector (20), which is fixed with a potting compound (8), and is positioned in the closed position in a wall (6) with a suitable bore (h) on a two-part protective cap (41+42) attached to a retaining cable (41). The nut (7) on the external thread (d) fixes the connector housing (1) to the wall (6). The retaining cable (41) extends into the connector housing (1) (e) and is secured against falling out of the connector housing (1) by a cable stop (42) and against falling out of the two-part protective cap (41+42) by a cable stop (44), and is also rotatably mounted (f) in the protective cap. Reference symbol list

[0020] a Bore for connector, b Bore for retaining element, c Thread for protective cap, d Thread for wall mounting, e Axial space for retaining element, f Rotatable bearing of the retaining element, g Protective cap thread, h Bore for connector housing, 1 Connector housing, 20 Connector, 21 Connector carrier, 22 Connector contacts, 3 Protective cap, 30 Two-part protective cap, 31 Outer part of the multi-part protective cap, 32 Inner part of the multi-part protective cap, 40 Retaining element, 41 Retaining cable, 42 Inner cable stop, 43 Terminal, 44 Outer cable stop, 5 Pin, 6 Wall, 7 Nut, 8 Potting compound QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2011 050 067 U1

[0003]

Claims

[1] Arrangement for a holding means (40) and protective cap (3), which can be screwed onto a connector housing (1) with a connector (20) arranged therein onto the mating thread (c) via a thread (g) and, when screwed on, the holding means (40) is completely enclosed in the protected area, characterized by that the protective cap is held captive on the connector housing. [2] Holding means (40) according to claim 1, characterized by that at least part of the holding means (40) can lie in the connector housing and can be pulled out again up to the cable stop (42) when unscrewing the protective cap (3). [3] Multi-part protective cap (30) according to claim 2, characterized by that a positive fit secures the protective cap captive to the holding means (40) via the cable stop (44).

Images