# US 10,312,623 B2 · Spring-loaded contacts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,312,623 B2 - Document ID: US10312623B2 - Status: Granted - Kind: B2 - Application number: 15/722,379 - Filed: 2017-10-02 - Published: 2018-03-29 - Granted: 2019-06-04 - Earliest claimed: 2011-10-12 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Min Chul Kim; John C. DiFonzo - Web page: https://patentgrep.com/patent/US10312623B2 ## CPC - H01R 13/2471: {pin shaped} - H01R 13/17: with spring member on the pin - H01R 13/2421: {using coil springs} - H01R 13/62: Means for facilitating engagement or disengagement of coupling parts or for holding them in engagement - H01R: ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS ## Abstract Spring-loaded contacts having an improved reliability. One example may provide spring-loaded contacts having a reduced likelihood of entanglement between a spring and a plunger. For example, a piston may be placed between a plunger and a spring. The piston may have a head portion that is wider than the diameter of the spring and located between the spring and the plunger to isolate the spring and the plunger. In these and other examples, an additional object, such as a sphere, may be placed between the plunger and spring. In another example, two additional objects, such as two spheres, may be placed between a plunger and piston. ## Claims ### Claim 1 A spring-loaded contact for an electrical connector, the spring-loaded contact comprising: a barrel having a cylindrical wall, the wall terminating at one end in a front opening; a plunger partially enclosed by the barrel and having a front portion extending through the front opening of the barrel, wherein a back surface of the plunger has an asymmetrical conical indentation formed in a tapered surface; a spring enclosed by the barrel; and a piston having a symmetrical dome-shaped head located between the back surface of the plunger and the spring and a body substantially surrounded by the spring, wherein the head of the piston contacts the plunger at the back surface of the plunger. ### Claim 2 (depends on 1) The spring-loaded contact of claim 1 wherein an apex of the conical indentation is off-center. ### Claim 3 (depends on 1) The spring-loaded contact of claim 1 wherein the cylindrical wall of the barrel has a narrowing portion at the front opening, and the plunger has a notch at a front edge of a widened portion, where the notch acts as a stop preventing the plunger from exiting the barrel. ### Claim 4 (depends on 1) The spring-loaded contact of claim 1 wherein the piston is formed using stainless steel and the spring is formed using stainless steel and is coated with a dielectric. ### Claim 5 (depends on 4) The spring-loaded contact of claim 4 wherein the dielectric is parylene. ### Claim 6 (depends on 1) The spring-loaded contact of claim 1 wherein the spring is gold-plated. ### Claim 7 (depends on 1) The spring-loaded contact of claim 1 wherein the barrel includes a vent. ### Claim 8 (depends on 1) The spring loaded contact of claim 1 wherein the plunger has a first length along a first side and a second length along a second side, the second side opposite the first side, the second length longer than the first length. ### Claim 9 (depends on 8) The spring-loaded contact of claim 8 wherein an apex of the conical indentation is off-center towards the first side of the plunger. ### Claim 10 A spring-loaded contact for an electrical connector comprising: a barrel having a cylindrical wall, the wall terminating at one end in a front opening; a plunger at least partially enclosed by the barrel and having a front portion extending through the front opening of the barrel; a spring enclosed by the barrel; and a piston having a symmetrical dome-shaped head located between the plunger and the spring and a body substantially surrounded by the spring, wherein a back surface of the plunger has an asymmetrical conical indentation formed in a tapered surface, and the plunger has a first length along a first side and a second length along a second side, the second length longer than the first length. ### Claim 11 (depends on 10) The spring-loaded contact of claim 10 wherein an apex of the conical indentation is off-center towards the first side of the plunger. ### Claim 12 (depends on 10) The spring-loaded contact of claim 10 wherein the cylindrical wall of the barrel has a narrowing portion at the front opening, and the plunger has a notch at a front edge of a widened portion, where the notch acts as a stop to keep the widened portion of the plunger in the barrel. ### Claim 13 (depends on 10) The spring-loaded contact of claim 10 wherein the piston is formed using stainless steel and the spring is formed using stainless steel and is coated with a dielectric. ### Claim 14 (depends on 13) The spring-loaded contact of claim 13 wherein the dielectric is parylene. ### Claim 15 (depends on 10) The spring-loaded contact of claim 10 wherein the barrel includes a vent. ### Claim 16 A spring-loaded contact for an electrical connector comprising: a barrel having a cylindrical wall, the wall terminating at one end in a front opening; a plunger at least partially enclosed by the barrel and having a front portion extending through the front opening of the barrel, wherein an entire back surface of the plunger has an off-center conical indentation formed in a tapered surface; a spring enclosed by the barrel; and a piston having a symmetrical dome-shaped head located between the back surface of the plunger and the spring and a body substantially surrounded by the spring, wherein the head of the piston contacts the plunger at the back surface of the plunger. ### Claim 17 (depends on 16) The spring-loaded contact of claim 16 wherein the barrel includes a vent. ### Claim 18 (depends on 16) The spring-loaded contact of claim 16 wherein the cylindrical wall of the barrel has a narrowing portion at the front opening, and the plunger has a notch at a front edge of a widened portion, where the notch acts as a stop to keep the widened portion of the plunger in the barrel. ### Claim 19 (depends on 18) The spring loaded contact of claim 18 wherein the plunger has a first length along a first side and a second length along a second side, the second side opposite the first side, the second length longer than the first length, and wherein an apex of the conical indentation is off-center towards the first side of the plunger.