For decades, the ultra small D-sub connector has been the standard interface for industrial applications. However, traditional D-sub connectors require time-consuming screw connections, greatly reducing installation and maintenance efficiency. This issue is particularly prominent in application scenarios that require frequent plugging and unplugging, such as testing equipment, production lines, and control panels. Designers need a solution that can maintain the reliability and wide compatibility of D-sub interfaces, while shortening connection time and ensuring electromagnetic compatibility (EMC).
This article briefly explains why D-sub is still widely used in the world of diverse connector choices in modern times. Then, HARTING's D-sub connection mechanism was introduced, and how the mechanism transformed the traditional D-sub structure into a tool free "one press, one connect" quick connection method, thereby reducing disassembly time while maintaining compatibility and reliability.
Why D-sub connectors are still important
D-sub connectors are almost ubiquitous in the fields of automation and control, robotics, and machine tools. They are also distributed throughout transportation infrastructure, testing equipment, and communication fields, including railways, semiconductor tools, and control networks.
This is not just a phenomenon of traditional infrastructure. D-sub still holds appeal as numerous suppliers offer multiple options. In addition to standard signal connectors, designers can also use hybrid layouts to integrate signals, power, and coaxial cables into one housing, making it a practical first choice for many designs. These connectors have also undergone decades of standardization and compliance testing, providing assurance for regulated industries such as transportation and railways.
Despite these advantages, D-sub is still not as easy to deploy and maintain as modern push-pull alternatives. However, as the technology is deeply embedded in existing infrastructure, it is not feasible to directly replace them. Introducing new connectors on top of the existing D-sub also poses challenges as it complicates inventory, tools, and training.
Upgrade D-sub connector with a straight push-pull mechanism
The HARTING D-sub push-pull mechanism (Figure 1) provides a convincing solution to this problem. The core of the device is a push-pull cover, which replaces the traditional D-sub rear shell. The push-pull cover is engaged with locking bolts and can be installed on existing top screw posts.
D-sub push-pull locking mechanism picture
Figure 1: The D-sub push-pull locking mechanism includes a push-pull cover (1) surrounding the rear shell and a locking bolt (2), which can be retrofitted onto existing plug-in columns (3). (Image source: HARTING, modified by Kenton Williston)
By replacing fixed screws with a "one press, one connect" locking mechanism, designers can enjoy the convenience of modern connectors while maintaining compatibility with D-sub technology that has been in use for decades. Most importantly, it can be added to existing devices without any modifications to the equipment; Just upgrade the cable components.
Bite and release are both simple. When connecting, press the cover directly into the bolt on one side of the device until a clear audible and tactile click sound is heard, confirming that it has been securely locked. To disconnect, the user only needs to pull the cover, and the locking device will disengage. With a smooth motion, the connector can be released. Even after hundreds of insertions and removals, the locking force remains consistent and repeatable, ensuring reliable performance during frequent equipment maintenance processes.
The push-pull mechanism has a wide range of uses, with two types of covers to choose from: plastic and metallized plastic. The housing size offers options 1, 2, and 3, which are suitable for standard 9-pin, 15 pin, and 25 pin connectors, respectively. The cover supports cables with a diameter of up to 14 millimeters (mm) and has one to three inlet ports to accommodate different cable directions.
The selection of locking bolts is equally flexible. There are two types of screws available: 4-40 UNC and M3, and front-end and back-end installation solutions are provided to accommodate common panel designs.