The present invention relates to electrical connectors, specifically connector pins, also known as terminals or terminal pins.
Electrical connectors of varying configurations may be used where blind mate insertion is required, for example in space constrained environments such as robot arms or fingers. During blind mate insertion, or insertion without visual assistance, distortion of the connector pins may occur from misalignment of the pins of one connector with the pins of the mating connector, and with the resulting physical interference preventing a successful electrical connection. This distortion may include bending of mating ends of the connector pin, bending of a portion of the connector pin from its central axis, collapse of the mating pin end or distortion of a flexible element of the pin mating end.
In applications which require numerous connections and disconnections of the connector, distortion of the connector pins may be cumulative, causing decreasing function and failure over time. In some applications, distortion may occur after assembly if the connectors are subject to certain detrimental conditions of use. Detrimental conditions of use may include, by example, excessive vibration, physical loading, thermal stressing, repetitive stressing, as in a push-pull or repetitive motion environment, for example as in a robot arm or manipulator, improper assembly, assembly without jack screws, or assembly with incomplete connection of other connector retention features.
Distortion of connector pins may render the connector unusable, resulting in, for example, unacceptable connector life, repair and replacement costs, loss of operating capability, decreased reliability and compromised integrity of the electrical connection. Existing solutions to prevent connector pin distortion are not adaptable to all operating environments. For example, alignment features added to the connector housing, or retention features such as secondary clips and tangs, may not be feasible in some applications where space constraints prohibit the larger housing size required for incorporating these features. An alternative solution to prevent distortion that is integral to or incorporated into the connector pin is advantageous to improving connector reliability in space constrained applications.
It is an object of the present invention to increase the durability of a connector pin, by improving the resistance of the connector pin to distortion upon insertion into a mating connector, including blind mate insertion of the type that may be required in a space constrained environment, such as, for example, a robot arm. An electrical connector is provided that is configurable for assembly to a mating electrical connector, including a connector housing with one or more connector pins. Each connector pin has a mating end of a female or male type. The connector pin may be of various configurations, for example, post, tube, blade, pin, or other configurations known by those of ordinary skill in the art.
An element made of conforming material, for example, an elastomer, epoxy or rubber type material, is incorporated into the connector pin such that the conforming element is in sufficient contact with the mating end of the connector pin, to provide support during assembly so as to prevent distortion of the mating end. The configuration of the conforming element may be rectangular, wedge, cylindrical, conical, annular, or of an alternate configuration as required to provide support to the particular configuration of the connector pin and the connector housing. The conforming element may be inserted into the interior of the mating end of the pin to provide a supportive element preventing distortion of the mating end during assembly. Alternatively, the conforming element may surround a portion of the exterior surface of the mating end to constrain the exterior surface and to prevent distortion during assembly. To ensure retention of the conforming element, and/or as a method of providing additional support to prevent distortion, an adhesive may be used to position and adhere the conforming element to the mating end of the connector pin.
The conforming element may be incorporated in the connector pin to form a connector pin assembly, prior to assembly of the connector pin into a connector housing. Alternatively, the conforming element may be incorporated in the connector pin after the connector pin has been assembled into a connector housing.
The conforming element provides support to the mating end of the connector pin to prevent distortion of the connector pin during assembly to the mating connector. Further, it improves the durability of the connector pin by increasing the pin's resistance to distortion during multiple disconnections and reconnections of the connector pin, and by increasing the resistance of the pin to distortion from other conditions of use such as, for example, misassembly, vibration, physical loading, thermal stressing, exposure to push-pull stressing or a repetitive motion environment, for example as in a robot arm or robot fingers. The present invention provides the benefits of improved connector pin durability, extended connector life, reduced costs of repair and maintenance, reduced equipment downtime and improved integrity of electrical connections.
The claimed invention is adaptable to many different types of electrical connector pins and connector housing combinations, and may be used in conjunction with other connector alignment and retention features. The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
With reference to the drawings, wherein like reference numbers refer to the same or similar components throughout the several views, and beginning with
Connector assembly 10 may be used in any application where establishing an electrical connection using a connector is desired. As an example, and without limiting the claimed invention, the connector assembly 10 may be used in a robot, to provide electrical connection to an arm or to fingers of the robot. In applications such as an arm or fingers of a robot, the connector assembly 10 and connector pins 14 may be positioned in a space constrained environment requiring blind mate insertions into a mating connector, and/or assembly without secondary retention devices, such as jack screws or retention tangs. Additionally, in an application such as an arm or fingers of a robot, the connector assembly 10 and connector pins 14 may be subjected to repeated disconnection and reconnection for service and adjustment, and repeated cyclical loading and exposure to push-pull stressing from a repetitive motion duty cycle, imposing distortive stresses to the connector assembly 10 and connector pins 14.
During assembly of connector assembly 10, the mating ends 20 of the tangs 16 of a connector pin 14 may be misaligned with the mating ends of a mating connector, causing an interfering condition which may result in deflection and distortion of one or more of the tangs 16 on one or more of the connector pins 14. Misalignment may be, for example, from blind insertion. Other factors contributing to misalignment may include, as an example, assembly in a space constrained environment where use of jack screws or other retention clips may not be feasible, or where space constraints prevent optimal alignment of the connector mating ends 20 and axes 18 of connector pins 14 with their like parts in the mating connector assembly prior to insertion.
Tangs 16 may distort or deflect in any of a number of configurations. Referring to
Some amount of deflection of the tangs 16 at mating ends 20 may be anticipated and tolerated during proper assembly. Referring to
When the amount of deflection of one or more of the tangs 16 of a connector pin 14 is significant, e.g., resulting in plastic deformation or permanent deflection of one or more of the tangs 16 due to misalignment and interference with the mating connector during an assembly attempt or as a result of mishandling or other damage, a number of conditions may result. When distortion of tangs 16 is significant enough to prevent the assembly of connector assembly 10 with a mating connector assembly, replacement of the damaged connector pin 14 or the entire connector assembly 10 may be required. This condition requires rework, repair or replacement of the connector assembly 10 and results in downtime, lost productivity and increased costs.
When distortion of connector pin 14 is significant, e.g., plastic deformation and permanent deflection of tangs 16 occur; it may be possible to assemble the connector assembly 10 to the mating connector assembly. In this second condition, the resulting electrical connection may lack electrical integrity in one or more circuits or have decreased reliability, e.g., may be more susceptible to electrical variability under certain operating conditions including vibration and push-pull stress conditions.
The electrical connection may fail qualification testing and replacement of the damaged connector pin 14 or the connector assembly 10 may be required. Again, this condition requires rework, repair or replacement of the connector assembly 10 and results in downtime, lost productivity and increased costs.
In a third condition, the distortion of tangs 16 may not be significant enough to prevent the assembly of connector assembly 10 with a mating connector assembly, or to cause failure of the electrical connection during initial qualification testing, and the somewhat distorted connector assembly may be put into use in a functional application. However, the distortion of connector pin 14 may result in decreased electrical integrity in one or more circuits after the connector assembly 10 is put to use, or decreased reliability over time, e.g., the electrical connection may be more susceptible to electrical variability under certain operating conditions including vibration and push-pull stress conditions. This condition may result in downtime, warranty costs and rework, repair or replacement of the connector 10. Distortion and deflection of the tangs 16 of connectors 14 may be cumulative, for example, as the result of multiple disconnections and reconnections of the connector during use or service, or as the result of stresses on the connector 14 while assembled, due to vibration, thermal or mechanical stressing of the connector assembly 10. The distortion may accumulate to a magnitude where the integrity of the electrical connection of pin 14 is compromised and the connector assembly 10 fails.
Referring to
Conforming element 22 may be made of a conforming material providing the desired supportive and functional properties, for example, elastomeric materials, plastic, epoxy based materials and rubber or rubber based materials, or similar material known to those skilled in the art, to prevent distortion and/or plastic deformation of the mating end of connector 14. The selection of conforming material may also be influenced by other requirements of the application, such as, for example, operating temperature, electrical conductivity, bonding characteristics, formability, elasticity and durometer. In the present invention, conforming element 22 is made of a rubber based material.
Additionally, conforming element 22 may be adhered to connector pin 24 with an adhesive (not shown) to improve retention of conforming element 22 in proper position for conforming element 22 to provide support to flexible members 16 and mating ends 20. The adhesive may be applied, for example, between the external surface of conforming element 22 and the internal surfaces of flexible members 16, in the areas where the conforming element 22 contacts the internal surfaces of flexible members 16. The adhesive may also contribute to provide support to the flexible members 16 and mating ends 20 to prevent distortion thereof. The adhesive may be, by example, of a silicone or epoxy type, or similar material known to those skilled in the art. The selection of adhesive material may also be influenced by other requirements of the application, such as, for example, operating temperature, electrical conductivity, bonding characteristics, elasticity and strength. The adhesive in the present invention is of a silicone RTV type.
The application of the present invention is not limited to a specific type of connector assembly, connector housing or connector pin. Conforming elements can be configured in various shapes and of various materials to be suitable for use with various types of connector pins, including, by example, female and male connector pins, and hollow and solid connector pins. The conforming element may be incorporated in the connector pin to form a connector pin assembly, prior to assembly of the connector pin into a connector housing. Alternatively, the conforming element may be incorporated in the connector pin after the connector pin has been assembled into a connector housing. Further, the conforming element may be incorporated in the connector pin after the connector pin has been assembled into a connector housing, and after the connector assembly has been incorporated into a larger assembly, as a repair method or durability enhancement feature.
Referring to
Flexible members 36 may become distorted and out of alignment from axis 38 of connector pin 34 as the result of improper alignment and/or interference upon insertion of connector pin 34 in a mating female connector pin, for example during insertion into the tangs 56 of connector pin 54 shown in
Referring to
As discussed for the conforming element 22 in the embodiment shown in
Also discussed previously, conforming element 42 may be adhered to connector pin 34 with an adhesive (not shown) to improve retention of conforming element 42 in proper position for conforming element 42 to provide support to flexible members 36 and mating end 30. The adhesive may be applied, for example, between one or more external surfaces of conforming element 42 and the internal surfaces of flexible members 36, in the areas where the conforming element 42 contacts the internal surfaces of flexible members 36. The adhesive may also contribute to provide support to the flexible members 36 and mating ends 30 to prevent distortion thereof. The adhesive may be, by example, of a silicone or epoxy type, or similar material known to those skilled in the art.
Referring to
Flexible members 56 may become distorted and out of alignment from axis 58 of connector pin 54 as the result of improper alignment or interference during assembly of connector pin 54 with a mating male connector pin, for example during insertion over the tangs 36 of connector pin 34 shown in
Referring to
As discussed for the conforming element 22 in the embodiment shown in
Also discussed previously, conforming element 62 may be adhered to connector pin 54 with an adhesive (not shown) to improve retention of conforming element 62 in proper position for conforming element 62 to provide support to flexible members 56 and mating ends 50. The adhesive may be applied, for example, between the portions of the internal surface of conforming element 62 and the external surfaces of flexible members 56, in the areas where the conforming element 62 contact the external surfaces of flexible members 56. The adhesive may also contribute to provide support to the flexible members 56 and mating ends 50 to prevent distortion thereof. The adhesive may be, by example, of a silicone or epoxy type, or similar material known to those skilled in the art.
While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
The present application claims the benefit of and priority to U.S. Provisional Application No. 61/174,316 filed on Apr. 30, 2009.
This invention was made with government support under NASA Space Act Agreement number SAA-AT-07-003. The government may have certain rights in the invention.
Number | Name | Date | Kind |
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2502634 | Smith | Apr 1950 | A |
3845459 | Normann | Oct 1974 | A |
5993253 | Sai | Nov 1999 | A |
Number | Date | Country | |
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20100279524 A1 | Nov 2010 | US |
Number | Date | Country | |
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61174316 | Apr 2009 | US |