This invention relates a force-biased spring probe pin.
A spring probe pin assembly is often also referred to as a Pogo™ pin. Pogo™ is a registered trademark of Xcerra Corporation in Norwood, Mass. A spring probe pin or Pogo™ assembly is a device used in electronics to establish an electrical connection between two circuits. Pogo™ pins are usually arranged in a dense array, connecting together many individual nodes of two circuits or circuit boards. Pogo™ pin connectors are commonly found in automatic test equipment (ATE) in the form of a bed of nails where they facilitate the rapid, reliable connection of the devices under test. A Pogo™ pin connector may contain just a few Pogo™ pins to many hundred Pogo™ pins. In one extremely high-density configuration, the array takes the form of a ring containing hundreds or thousands of individual pogo pins; this device is sometimes referred to as a pogo tower.
Pogo™ pin connectors are also commonly used to form reliable, non permanent electrical contacts in electrical equipment. For example an electronic device with multiple electrical connections may be plugged into an piece of electrical equipment and secured in place for example by a snap connector, a spring, or screws. A Pogo™ pin connector may be used to establish electrical connection. An electronic device installed in electrical equipment in this manner may be easily be removed and replaced without the need of special equipment. This is especially convenient for repairing or updated electrical equipment in the field. For example, Pogo™ pin connectors are used for the installation of devices in the Cray 2 computer.
As shown in
The spring 108 forces the plunger 104 (or plungers 204 and 210 in
Although the spring 108 typically forms an electrical path in parallel with the cylindrical barrel member 106 of the spring probe pin assembly, the resistance of the spring is typically so much higher than the resistance of the wall of the barrel member 106 that an insignificant amount of current flows through the spring 108.
A common problem that may arise with a conventional spring probe pin assembly 300 during use is illustrated in
The following presents a simplified summary in order to provide a basic understanding of one or more aspects of the invention. This summary is not an extensive overview of the invention, and is neither intended to identify key or critical elements of the invention, nor to delineate the scope thereof. Rather, the primary purpose of the summary is to present some concepts of the invention in a simplified form as a prelude to a more detailed description that is presented later.
A force-biased spring probe pin assembly includes a barrel member having a barrel wall defining an elongate internal cavity with a lower end and an upper end. The assembly also includes a first plunger member reciprocally mounted in the internal cavity proximate the lower end of the internal cavity. A spring member is positioned in the internal cavity between the plunger member and the second end of the internal cavity. At least one rectangular cavity formed in the plunger member with a movable cylindrical bearing in the cavity that applies a slight transverse force to the plunger member ensuring good electrical contact between the plunger and the wall of the barrel member. A force-biased spring probe pin assembly includes a barrel member having a barrel wall defining an elongate internal cavity with a lower end and an upper end. The assembly also includes a first plunger member reciprocally mounted in the internal cavity proximate the lower end of the internal cavity and a second plunger member reciprocally mounted in the internal cavity proximate the upper end of the internal cavity. A spring member is positioned in the internal cavity between the first plunger member and the second plunger member. At least one rectangular cavity formed in the first plunger member with a first movable cylindrical bearing in the cavity that applies a slight transverse force to the first plunger member ensuring good electrical contact between the first plunger member and the wall of the barrel member and at least one rectangular cavity formed in the second plunger member with a second movable cylindrical bearing in the cavity that applies a slight transverse force to the second plunger member ensuring good electrical contact between the second plunger member and the wall of the barrel member.
Embodiments of the invention are described with reference to the attached figures. The figures are not drawn to scale and they are provided merely to illustrate the invention. Several aspects of the embodiments are described below with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide an understanding of the invention. One skilled in the relevant art, however, will readily recognize that the invention can be practiced without one or more of the specific details or with other methods. In other instances, well-known structures or operations are not shown in detail to avoid obscuring the invention. The embodiments are not limited by the illustrated ordering of acts or events, as some acts may occur in different orders and/or concurrently with other acts or events. Furthermore, not all illustrated acts or events are required to implement a methodology in accordance with the present invention.
As used herein “force-biased spring probe pin assembly” refers to a spring probe pin assembly that has been modified to apply a slight force that ensures good electrical contact between the plunger and the cylindrical barrel to avoid significant current from flowing through and damaging the spring.
Embodiment force-biased spring probe pin assemblies are illustrated in
As is illustrated in
As is illustrated in
Alternatively as shown in
One movable cylindrical bearing 420 is shown in
As is illustrated in
While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only and not limitation. Numerous changes to the disclosed embodiments can be made in accordance with the disclosure herein without departing from the spirit or scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above described embodiments. Rather, the scope of the invention should be defined in accordance with the following claims and their equivalents.
The following co-pending patent applications are related and hereby incorporated by reference: U.S. patent application Ser. No. 14/______ (Texas Instruments docket number TI-76145, filed simultaneously with this application, U.S. patent application Ser. No. 14/______ (Texas Instruments docket number TI-76146, filed simultaneously with this application, and U.S. patent application Ser. No. 14/______ (Texas Instruments docket number TI-76412, filed simultaneously with this application With the mention in this section, these patent applications are not admitted to be prior art with respect to the present invention This application is related to patent application Ser. No. 14/863,198 (Attorney Docket Number TI-75273, filed Sep. 23, 2015, entitled “Spring Biased Probe Pin Assembly,” with its mention in this section, this patent application is not admitted to be prior art with respect to the present invention.