SPRING PIN CONNECTOR

Abstract

 Spring pin connector, comprising:
- a female housing (10 ; 10') comprising a hole (12 ; 12') defining an axial direction (XX'),
- a pin (20), provided moveable in the hole (12 ; 12') of the female housing (10 ; 10') along the axial direction (XX'), between a rest position and a connecting position,
- a spring (30), arranged between the pin (20) and a ground surface (11) of the female housing (10 ; 10') to generate a pushing force, so as to push the pin (20) into the rest position,
characterized in that the ground surface (11) is inclined and/or asymmetric relative to the axial direction (XX').

Description

[0001] The present invention relates to a spring pin connector, typically used in electric or electronical devices to provide connections with printed circuits, electric pads, electric terminals.

[0002] As illustrated in documents WO2017159155A1 or US9941627B2, spring pin connectors typically comprise a pin, provided moveable in a housing, and a spring, arranged to push the pin from a connecting position to a rest position. To avoid micro cuts, it is known to provide a slanted or biased pushed surface onto the pin. However, this design is not compact and/or limits the maximum axial stroke of the pin.

[0003] The present invention aims to address the above mentioned drawbacks of the prior art, and to propose first a spring pin connector with micro cuts protection, and a maximized stroke, with a compact design.

[0004] In this aim, a first aspect of the invention is directed to a spring pin connector, comprising:

• a female housing comprising a hole, the hole defining an axial direction,
• a pin, provided moveable in the hole of the female housing along the axial direction, between a first position and a second position,
• a spring, arranged between the pin and a ground surface of the female housing to generate a pushing force on the pin, so as to push the pin into the first position,

characterized in that the ground surface is inclined and/or asymmetric relative to the axial direction.

[0005] The spring pin connector according to the above embodiment comprises a ground surface which is inclined versus the axial direction, and which is opposite to the pin. Due to this inclination, the spring pushes the pin with a non axial or non aligned pushing force, creating a tilting of the pin and thus a lateral contact between the pin and the housing, so as to provide the avoidance of micro cuts. Since the ground surface is provided on the housing side, the pin can be provided with a non inclined / symmetric pushed surface, and then a blind hole can be implemented in the pin to accommodate the spring so as to minimize the axial length of the connector. The design is rendered compact, and/or the spring can be designed with an increased length so as to decreased internal stress to maximize the number of connexions.

[0006] Advantageously, the first position is a rest position, and the second position is a connecting position.

[0007] In other words, the invention relates to a spring pin connector, comprising:

• a female housing comprising a hole defining an axial direction,
• a pin, provided moveable in the hole of the female housing along the axial direction, between a rest position and a connecting position,
• a spring, arranged between the pin and a ground surface of the female housing to generate a pushing force, so as to push the pin into the rest position,

characterized in that the ground surface is inclined and/or asymmetric relative to the axial direction

[0008] In other words, the invention relates to a spring pin connector, comprising:

• a female housing comprising a hole defining an axial direction,
• a pin, provided moveable in the hole of the female housing along the axial direction, between a rest position and a connecting position,
• a spring, arranged between the pin and a ground surface of the female housing to generate a pushing force, so as to push the pin into the rest position,

wherein the spring contacts the ground surface via a contacting surface, characterized in that the contacting surface is comprised within a plane which is inclined relative to the axial direction. The contacting surface is on the housing side, so that the pin can be designed with a blind hole having a symmetric end surface, so that on one hand the pin is pushed / tilted / misaligned to ensure lateral contact with the housing, and the design is compact, as the spring can be partially arranged into the pin.

[0009] In other words, the invention relates to a spring pin connector, comprising:

• a female housing comprising a hole defining an axial direction,
• a pin, provided moveable in the hole of the female housing along the axial direction, between a rest position and a connecting position,
• a spring, arranged between the pin and a ground surface of the female housing to generate a pushing force, so as to push the pin into the rest position into which an abutment surface of the pin rests in contact with an abutment surface of the housing,

characterized in that the ground surface is inclined and/or asymmetric relative to the axial direction, so as to offset the pushing force relative to the axial direction.

[0010] In other words, the invention relates to a spring pin connector, comprising:

• a female housing comprising a hole defining an axial direction,
• a pin, provided moveable in the hole of the female housing along the axial direction, between a rest position and a connecting position,
• a spring, arranged between the pin and a ground surface of the female housing to generate a pushing force,

characterized in that the ground surface is inclined and/or asymmetric relative to the axial direction, so as to offset the pin relative to the axial direction when the pin is pushed from the rest position to the connecting position.

[0011] Advantageously, the spring contacts the pin via a pushed surface which is perpendicular and/or symmetric relative to the axial direction. Since the surface on the housing side is slanted, it is not necessary to implement a slanted surface on the pin side to provide the micro cuts avoidance.

[0012] Advantageously, the pin comprises a blind hole, and the spring is at least partially arranged into the blind hole. The length of the spring connector is short, and the connector is still easy to manufacture, as the blind hole end does not need to be implemented with a slanted surface.

[0013] Advantageously, the blind hole comprises a conical end, typical of a drilling process.

[0014] Advantageously, the female housing comprises:

• a body, comprising the hole,
• a cap, fixed to the body and comprising the ground surface. Providing the female housing with two separate parts allows to simplify the manufacturing, as the cap comprises the ground surface which is slanted relative to the axial direction, avoiding the need to machine the housing with a blind hole (to guide the spring), with an end surface slanted or asymmetric relative to the axial direction.

[0015] Advantageously, the cap is press fit into the hole. This design is reliable and cost effective.

[0016] Advantageously, the cap comprises at least one shoulder arranged in contact with the body. Axial position of the ground surface is defined by construction.

[0017] Advantageously, the cap comprises at least one rear shoulder and/or rear pin arranged opposite to the ground surface.

[0018] Advantageously, the female housing comprises a crimped portion for defining an abutment surface to the pin into the rest position.

[0019] Advantageously, the ground surface is inclined to the axial direction in a range of [70° - 88°], preferably in a range of [74° - 85°] and more preferably in a range of [75° - 80°].

[0020] A second aspect of the invention relates to an electronic device, comprising at least one spring pin connector according to the first aspect of the invention.

[0021] Other features and advantages of the present invention will appear more clearly from the following detailed description of particular non-limitative examples of the invention, illustrated by the appended drawings where:

• figure 1 represents a first embodiment of a spring pin connector according to the invention ;
• figure 2 represents a second embodiment of a spring pin connector according to the invention ;
• figures 3a, 3b, 3c represent several embodiments of spring pin connectors according to the invention.

[0022] The figure 1 represents a spring pin connector comprising a female housing 10 made of a body 10a and a cap 10b. The body 10a comprises a hole 12 presenting an axial direction XX', into which a pin 20 is arranged to slide or translate. A spring 30 is arranged between a ground surface 11 of the cap 10b and an end surface of a blind hole of the pin 20, to push the pin 20 to the right side of figure 1, in a rest position as represented. In this rest position, a shoulder 20a of the pin 20 abuts against a crimped portion of the body 10a.

[0023] In service, when the spring pin connector connects a mating surface, the pin 20 is pushed to the left (against the pushing force of the spring 30), into a connecting position. In such connecting position, there is a clearance between the shoulder 20a of the pin 20 and the crimped portion of the body 10a.

[0024] To still achieve a good and correct electric contact between the pin 20 and the body 10a, the ground surface of the cap 10b is slanted respectively to the axial direction XX' with angle α, so that the spring 30 has a contact surface with cap 10b not perpendicular to the axial direction XX'. Typically, angle α is in the range of [70° - 88°], preferably in a range of [74° - 85°] and more preferably in a range of [75° - 80°]. Ideally, angle α has a value of 78°.

[0025] As a consequence, the spring 30 exerts a pushing force to the pin 20 which is misaligned / biased versus the axial direction, then the pin 20 is tilted or tends to tilt into the hole 12 (as shown by the curved arrow on figure 1), so that there is lateral contact between the pin 20 and hole 12, thus providing a reliable and constant electric contact between pin 20 and hole 12. Micro cuts are avoided.

[0026] This design, with cap 10b having a slanted contact surface for spring 30 allows to install the spring 30 into the blind hole of the pin 20, so as to minimize the overall axial length of the connector, and allows to manufacture the pin 20 with standard machining process, for the blind hole, which can present an end with the standard conical and symmetric shape, typical from a drilling machining.

[0027] The cap 10b of figure 1 is press fitted into a corresponding hole of the body 10a, but has a shorter length, so that the left end of the spring 30 is self centred by the body 10a. Manufacturing of such cap 10b with its slanted ground surface 11 does not require complex tooling, and the assembly is cheap.

[0028] The spring pin connector according to the invention is simple to manufacture, presents a short axial length, still with a micro cuts protection and a long stroke for pin 20, which can easily compensate for dimensional tolerances of the electronic device into which it is installed. Also, for a given mated height, the stress in the spring is reduced, thereby enabling a larger number of compressions of the spring (mating cycles).

[0029] Figure 2 represents a second embodiment of a spring pin connector according to the invention. Similarly to the first embodiment, the spring 30 contacts the ground surface 11 which is inclined or slanted to generate a misaligned pushing force and to tilt or bias the pin 20.

[0030] However, in this embodiment, female housing 10' comprises a body 10'a which has a straight internal hole 12', and a cap 10'b which comprises a rear shoulder and rear pin, to provide another fixing interface for the connector.

[0031] Figures 3a - 3c represent various designs of spring pin connectors, in rest position (left view) and with pin fully pushed (right view). Figure 3a represents a design where the cap has a bottom or rear flat surface, for being soldered onto a support. Fig 3b represents a design where the cap has a bottom or rear shouldered surface with a rear pin for being introduced into a hole of the support, for "intrusive reflow soldering", also called "pin in paste" soldering. Fig. 3c represents a design where the cap has a bottom or rear shouldered surface with a rear pin for being introduced into a through hole of a support and soldered thereafter.

[0032] In general, the housing (cap, body part) and pin are machined from brass or other copper alloy or other conductive metals / alloys. The parts are post-plated with any one of a variety of coatings for the purpose of good electrical contact and wear and corrosion resistance.

[0033] The spring is made from any one a variety of materials, such as stainless steel, Beryllium copper, high carbon steel such as music wire, or high-temperature alloys.

[0034] Typically, the spring pin connector has an effective length comprised in the range of [1.5 - 10] mm, the female housing has an outer diameter comprised in the range of [0.5 - 8] mm, the pin has an outer diameter comprised in the range of [0.25 - 6] mm, and a stroke comprised in the range of [0.25 - 5] mm.

[0035] It is of course understood that obvious improvements and/or modifications for one skilled in the art may be implemented, still being under the scope of the invention as it is defined by the appended claims.

Claims

1. Spring pin connector, comprising:

- a female housing (10 ; 10') comprising a hole (12 ; 12'), the hole (12 ; 12') defining an axial direction (XX'),

- a pin (20), provided moveable in the hole (12 ; 12') of the female housing (10 ; 10') along the axial direction (XX'), between a first position and a second position,

- a spring (30), arranged between the pin (20) and a ground surface (11) of the female housing (10 ; 10') to generate a pushing force on the pin (20), so as to push the pin (20) into the first position,

characterized in that the ground surface (11) is inclined and/or asymmetric relative to the axial direction (XX').

2. Spring pin connector according to the preceding claim, wherein, the spring (30) contacts the pin (20) via a pushed surface which is perpendicular and/or symmetric relative to the axial direction (XX').

3. Spring pin connector according to any one of the preceding claims, wherein the pin (20) comprises a blind hole, and wherein the spring (30) is at least partially arranged into the blind hole.

4. Spring pin connector according to the preceding claim, wherein the blind hole comprises a conical end.

5. Spring pin connector according to any one of the preceding claims, wherein the female housing (10 ; 10') comprises:

- a body (10a ; 10'a), comprising the hole (12 ; 12'),

- a cap (10b ; 10'b), fixed to the body (10a ; 10'a) and comprising the ground surface (11).

6. Spring pin connector according to the preceding claim, wherein the cap (10b ; 10'b) is press fit into the hole (12 ; 12').

7. Spring pin connector according to any one of the claims 4 to 5, wherein the cap (10b ; 10'b) comprises at least one shoulder arranged in contact with the body (10a ; 10'a).

8. Spring pin connector according to any one of the claims 4 to 6, wherein the cap (10b ; 10'b) comprises at least one rear shoulder and/or rear pin (20) arranged opposite to the ground surface (11).

9. Spring pin connector according to any one of the preceding claims, wherein the female housing (10 ; 10') comprises a crimped portion for defining an abutment surface to the pin (20) into the first position.

10. Spring pin connector according to any one of the preceding claims, wherein the ground surface (11) is inclined to the axial direction (XX') in a range of [70° - 88°], preferably in a range of [74° - 85°] and more preferably in a range of [75° - 80°].

11. Electronic device, comprising at least one spring pin connector according to any one of the preceding claims.

Drawing