# Patent

## Title
Low profile circuit connector

## Abstract

An electrical connector includes a housing, contact elements and locking members attached to the housing. The housing has a front end, a back end, a top side, a bottom side and a cavity between the top side and the bottom side. The cavity is to partially receive a circuit board therein. Each contact element is insertable into the housing along a direction from the bottom side towards the top side. Each locking member is insertable into the housing along a direction from the bottom side towards the top side. The upper and lower contact arms and the lock arm are resiliently deflectable away from the cavity to allow insertion of the circuit board into the cavity, and spring back when the circuit board is inserted into the cavity to make electrical connection to the circuit board and to lock the circuit board in the housing.

## Background
TECHNICAL FIELD
The present invention relates to an electrical connector and in particular, the present invention relates to an electrical connector for connecting to a flexible printed circuit board.
BACKGROUND
Flexible Printed Circuit (FPC) board or ribbon connectors are used in many electronic devices for establishing electrical connections between different modules/components in the device. To ensure reliable connection, the connector is typically provided with an actuator for physically fixing and locking the FPC to the connector. Actuator is a movable element in an FPC connector, hence to enable effective operation of the actuator, the FPC connector must have a housing structure sufficiently large to physically support the actuator. In applications of compact sized electronic devices, the connectors used in such devices are miniaturized, and the housing of such miniaturized connectors may not have the required dimension, strength and/or rigidity to support an actuator and therefore electrical connection maybe compromised. It is therefore desireable to provide an FPC connector having a compact size and yet is capable to ensure reliable electrical connection with the FPC.
SUMMARY OF INVENTION
Embodiments of the present invention provide connectors for reliably connecting to an FPC without the need of an actuator. The connector can be made low profile, small and thinner to meet miniaturization requirements for use in compact electronics devices. The FPC can be securely fixed to the connector to establish and maintain electrical connection.
In one embodiment, an FPC connector has a housing and contact elements disposed in the housing. The housing has a front end, a back end, a top side, a bottom side and a cavity between the top side and the bottom side. Each contact element has an upper contact arm disposed at the top side and a lower contact arm disposed at the bottom side. The cavity is to receive a circuit board e.g. and FPC therein to establish electrical connection with the upper and lower contact arms. A pair of locking members is attached to the housing. Each locking member has a lock arm positioned along a direction from the back end to the front end of the housing. The upper contact arm and the lower contact arm of each contact element and the lock arm of each locking member are resiliently deflectable away from the cavity to allow insertion of the FPC into the cavity. When the circuit board is inserted into the cavity, the upper contact arm and the lower contact arm are in electrical contact with the FPC, and the lock arm springs back to engage the FPC and lock the circuit board to the housing.



BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are disclosed hereinafter with reference to the drawings, in which:
FIG. 1A is a perspective view showing an FPC connector according to one embodiment of the present invention;
FIG. 1B is a perspective bottom view of FIG. 1A;
FIG. 2 is an exploded view of FIG. 1A;
FIG. 3 is a perspective bottom view of the housing of the FPC connector showing in FIG. 1A;
FIG. 4 is a perspective view showing a contact element of the FPC connector showing in FIG. 1A;
FIG. 5 is a cross sectional view of FIG. 1A along A-A;
FIG. 6 is a perspective view showing a locking member of the FPC connector showing in FIG. 1A;
FIG. 7 is a cross sectional view of FIG. 1A along B-B;
FIG. 8 is a perspective view showing an FPC to be connected to the FPC connector of FIG. 1A;
FIG. 9 is a perspective view showing an FPC connected to the FPC connector of FIG. 1A;
FIG. 10 is a perspective cross sectional view of FIG. 9 along C-C;
FIG. 11 is a perspective cross sectional view of FIG. 9 along D-D.
FIG. 12A is a perspective view showing an FPC connector according to another embodiment of the present invention;
FIG. 12B is a perspective bottom view of FIG. 1A;
FIG. 13 is an exploded view of FIG. 12B;
FIG. 14 is a perspective view showing a contact element of the FPC connector showing in FIG. 12A;
FIG. 15 is a cross sectional view of FIG. 12A along A-A;
FIG. 16 is a perspective view showing a locking member of the FPC connector showing in FIG. 12A;
FIG. 17 is a cross sectional view of FIG. 12A along B-B;
FIG. 18 is a perspective view showing an FPC to be connected to the FPC connector of FIG. 12A;
FIG. 19 is a perspective view showing an. FPC connected to the FPC connector of FIG. 12A;
FIG. 20 is a perspective cross sectional view of FIG. 19 along C-C;
FIG. 21 is a perspective cross sectional view of FIG. 19 along D-D.



DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1A and FIG. 1B, an FPC connector 10 according to one embodiment of the present invention includes a housing 12, a plurality of contact elements 14, a pair of locking members 16 and a pair of hold downs 18 attached to housing 12. Housing 12 is made of molded plastic and has a front side 12a, back side 12b, top side 12c and bottom side 12d. Between top side 12c and bottom side 12d there is formed a cavity 12e for receiving an FPC therein to establish electrical connection.
As shown in FIGS. 2 and 3, housing 12 includes first contact grooves 124 formed at bottom side 12d and second contact grooves 126a formed on top side 12c. Formed on top side 12c are also fixing grooves 126b which extends to back side 12b of housing 12. In addition, hold down grooves 138 and fixing recesses 128a are formed on top side 12c, and fixing holes 128b are formed at bottom side 12d of housing 12.
As shown in FIG. 4, contact element 14 includes a base 140 and a tail 142 extending from base 140 towards a back side of contact element 140. A lower arm 144 and an upper arm 146 extend from base 140 towards a front side of contact element 140. Lower arm 144 has a lower contact projection 144a formed at a free end thereof, facing upper arm 146. Upper arm 146 has an upper contact projection 146a formed at a free end thereof, facing lower arm 144. Lower arm 144 and upper arm 146 define a space 145 therebetween for receiving an FPC. A fixing projection 148 is formed on base 140 and extending upwardly from base 140.
To assemble to housing 12, as shown in FIG. 5, each contact elements 14 is inserted and attached to housing 12 from bottom side 12d along a direction towards top side 12c, with fixing projection 148 inserted into fixing recess 128a. During the insertion process, upper arm 146 passes through first contact groove 124 and cavity 12e. When fixing projection 148 is fully received in fixing recess 128a, upper arm 146 is positioned in second contact groove 126a. Base 140 becomes in contact with first stopper(s) 134 formed in housing 12 hence further insertion of contact element 14 toward top side 12c is prevented. Meanwhile, lower arm 144 is received in first contact groove 124 and tail 142 is positioned at back side 12b of housing 12. Contact elements 14 are attached to housing 12 in this manner. Lower arm 144 is elastically deflectable within first contact groove 124. Likewise, upper arm 146 is elastically deflectable within second contact groove 126a. 
As shown in FIG. 6, locking member 16 includes a base 160 and a tail 162 extending backwardly and downwardly from base 160. A locking arm 166 extends forwardly from base 160 and has a catch member 166a formed at the free end of locking arm 166. Formed on base 160 there is a locking projection 168 extending downwardly.
To assemble to housing 12, as shown in FIG. 7, each locking member 16 is inserted to housing 12 from top side 12c along a direction towards bottom side 12d, with locking projection 168 inserted into fixing hole 128b of housing 12. When locking projection 168 is fully received in fixing hole 128b, locking arm 166 is positioned in fixing groove 126b. Base 160 becomes in contact with second stopper(s) 136 formed in housing 12 hence further insertion of locking member 16 toward bottom side 12d is prevented. Meanwhile, tail 162 is positioned at back side 12b of housing 12. Locking members 16 are attached to housing 12 in this manner, and locking arm 166 is allowed to deflect within fixing groove 126b. 
In use, as shown in FIGS. 8 to 11, an FPC 20 is inserted into cavity 12e of housing 12 from front side 12a to establish electrical connection with connector 10. As lower and upper arms 144, 146 and locking arm 166 are deflectable due to their elastic characteristics, during the insertion process, FPC 20 will cause lower arm 144 and upper arm 146 to deflect away from each other, hence contact portions 246a of FPC 20 can be positioned between lower arm 144 and upper arm 146, and become electrically connected to lower contact projection 144a and upper contact projection 146a (FIG. 10). During the insertion process, FPC 20 also pushes catching member 166a and causes locking arm 166 of locking member 16 to deflect upwardly. When FPC 20 is at the fully inserted position, as shown in FIG. 11, engagement notch 266a of FPC 20 is positioned under catching member 166a to allow locking arm 166 to resume to original position, such that catching member 166a engages FPC 20 at notch 266a. Disengagement or dropping off of FPC 20 from connector 10 can therefore be prevented.
As shown FIG. 12A, 12B and 13, an FPC connector 30 according to another embodiment of the present invention includes a housing 32, a plurality of contact elements 34, a pair of locking members 36 and a pair of hold downs 38 attached to housing 32. Housing 32 is made of molded plastic and has a front end 32a, back end 32b, top side 32c and bottom side 32d. Between top side 32c and bottom side 32d there is formed a cavity 32e for receiving an FPC therein to establish electrical connection with contact elements 34.
Housing 32 includes first contact grooves 324a and first fixing grooves 326a formed at bottom side 32d. Housing 32 also includes second contact grooves 324b and second fixing grooves 326b formed on top side 32c. Fixing holes 328 are formed in housing 32 from top side 32c through bottom side 32d. 
As shown in FIG. 14, contact element 34 has a base 340 and a tail 342 extending from base 340 toward a back side (right side in FIG. 14) of contact element 340. A lower arm 344 and an upper arm 346 extend from base 340 toward a front side (left side in FIG. 14) of contact element 34. Lower arm 344 has a lower contact projection 344a formed at a free end thereof, facing upper arm 346. Upper arm 346 has an upper contact projection 346a formed at a free end thereof, facing lower arm 344. Lower arm 344 and upper arm 346 form a space 345 therebetween, for receiving an FPC. A fixing projection 348 is formed on base 340 and extending upwardly from base 340.
To assemble to housing 32, as shown in FIG. 15, each contact element 34 is inserted and attached to housing 32 from bottom side 32d towards top side 32c, with fixing projection 348 inserted into fixing hole 328. During the insertion process, upper arm 346 passes through first contact groove 324a and cavity 32e. When fixing projection 348 is fully received in fixing hole 328, upper arm 346 is positioned in second contact groove 326b. Meanwhile, lower arm 344 is received in first contact groove 324 and tail 342 is positioned at back side 32b of housing 32. Base 340 becomes in contact with first stopper(s) 334 formed in housing 32, hence further movement of contact element 34 toward top side 32c is prevented. Lower arm 344 is elastically deflectable within first contact groove 324a. Likewise, upper arm 346 is elastically deflectable within second contact groove 324b. 
As shown in FIG. 16, locking member 36 includes a base 360 and a tail 362 extending backwardly from base 360. A locking arm 366 extends forwardly from base 360, and is offset from base 360 along a direction perpendicular to base 360. Locking arm 366 has a catch member 366a formed at the free end of locking arm 366, and faces downward. A locking projection 368 extends upwardly from base 360. The front end of locking arm 366 may be tapered, e.g. at a downward angle α.
To assemble to housing 34, as shown in FIG. 17, each locking member 36 is inserted into housing 32 from bottom side 32d along a direction towards top side 32c, with locking arm 366 passing through first fixing groove 326a, and locking projection 368 inserted into fixing hole 328 of housing 32. When locking projection 368 is fully received in fixing hole 328, locking arm 366 is positioned in second fixing groove 326b at top side of housing 32. At this position, catch member 366a is disposed in cavity 32e and faces downward. Base 360 becomes in contact with second stoppers 336 formed in housing 32, hence further insertion of locking member 36 toward top side 32c of housing 32 is prevented. Meanwhile, tail 362 is positioned at back side 32b of housing 32. Locking members 36 are attached to housing 32 in this manner, and locking arm 366 is allowed to deflect within second fixing groove 326b. 
In use, as shown in FIGS. 18 to 21, an FPC 40 is inserted into cavity 32e of housing 32 from front side 32a to establish electrical connection with connector 30. As lower and upper arms 344, 346 and locking arm 366 are deflectable due to their elastic characteristics, during the insertion process, FPC 40 will cause lower arm 344 and upper arm 346 to deflect away from each other, hence contact portions 346a of FPC 40 can be positioned between lower arm 344 and upper arm 346, and is electrically connected to lower contact projection 344a and upper contact projection 346a (FIG. 20).
During the insertion process, FPC 40 also acts against catching member 366a and causes locking arm 366 of locking member 36 to deflect upwardly. As second stoppers 336 acts against base 360 of locking arm 36, upward-deflection of locking arm 366 will have a tendency to tighten the attachment of locking member 36 to housing 32. As such, movement of locking member 36 relative to housing 32, and/or detachment of locking member 36 from housing 32 during the insertion process of FPC to connector 30, is prevented.
When FPC 40 is at the fully inserted position, as shown in FIG. 21, engagement notch 466a of FPC 40 is positioned under catching member 366a to allow locking arm 366 to resume to original position, such that catching member 366a engages FPC 40 at notch 466a. Disengagement or dropping off of FPC 40 from connector 30 can therefore be prevented and hence the electrical connection between FPC 40 and connector 30 is ensured.
Although embodiments of the present invention have been illustrated in conjunction with the accompanying drawings and described in the foregoing detailed description, it should be appreciated that the present invention is not limited to the embodiments disclosed. Therefore, the present invention should be understood to be capable of numerous rearrangements, modifications, alternatives and substitutions without departing from the spirit of the invention as set forth and recited by the following claims.

## Claims

1. An electrical connector, comprising:
a housing having a front end, a back end, a top side, a bottom side and a cavity between the top side and the bottom side, wherein the cavity is to receive a circuit board therein and the housing comprises a plurality of parallel grooves, with a first portion of the plurality of grooves comprising contact grooves and a second portion of the plurality of grooves comprising fixing grooves;
a plurality of contact elements disposed within the contact grooves and attached to the housing, each contact element having an upper contact arm disposed at the top side and a lower contact arm disposed at the bottom side;
a pair of locking members disposed within the fixing grooves and attached to the housing, each locking member having a lock arm positioned along a direction from the back end to the front end of the housing,
wherein the upper contact arm and the lower contact arm of each contact element and the lock arm of each locking member being resiliently deflectable away from the cavity to allow insertion of the circuit board into the cavity,
wherein when the circuit board is inserted into the cavity, the upper contact arm and the lower contact arm are in electrical contact with the circuit board, and the lock arm springs back to engage the circuit board and lock the circuit board to the housing, and
wherein the contact elements and locking members each comprises a tail extending from the housing to form an array of parallel tails extending from the back end of the housing.

2. The electrical connector of claim 1, wherein each locking member has a base and a locking projection extending perpendicularly from the base, wherein the housing has a plurality of fixing holes, when the locking members are attached to the housing, the locking projection of each locking member is positioned in a fixing hole along a direction perpendicular to the top side and the bottom side of the housing.

3. The electrical connector of claim 2, wherein the fixing holes are positioned at the bottom side of the housing, wherein the lock arm of each locking member is in alignment with the base such that when the locking projection is inserted into the fixing hole from the top side of the housing, the base and the lock arm are positioned at the top side of the housing.

4. The electrical connector of claim 3, wherein each locking member further comprising a catch member formed at an end portion of the lock arm, the catch member extends from the lock arm along a direction the same as the locking projection.

5. The electrical connector of claim 4, wherein when the locking projection is positioned in the fixing hole, the locking projection faces the bottom side of the housing and the catch member is disposed in the cavity and faces the bottom side of the housing.

6. The electrical connector of claim 5, wherein when the circuit board is inserted into the cavity, the catch member engages the circuit board to prevent the detachment of the circuit board from the housing.

7. The electrical connector of claim 1, wherein the plurality of contact elements and the pair of locking members are planar members.

8. An electrical connector, comprising:
a housing having a front end, a back end, a top side, a bottom side and a cavity between the top side and the bottom side, wherein the cavity is to receive a circuit board therein;
a plurality of contact elements attached to the housing, each contact element having an upper contact arm disposed at the top side and a lower contact arm disposed at the bottom side;
a plurality of locking members attached to the housing, each locking member having a lock arm positioned along a direction from the back end to the front end of the housing,
wherein the upper contact arm and the lower contact arm of each contact element and the lock arm of each locking member being resiliently deflectable away from the cavity to allow insertion of the circuit board into the cavity, and
wherein when the circuit board is inserted into the cavity, the upper contact arm and the lower contact arm are in electrical contact with the circuit board, and the lock arm springs back to engage the circuit board and lock the circuit board to the housing,
wherein each locking member has a base and a locking projection extending perpendicularly from the base, wherein the housing has a plurality of fixing holes, when the locking members are attached to the housing, the locking projection of each locking member is positioned in a fixing hole along a direction perpendicular to the top side and the bottom side of the housing,
wherein the fixing holes are positioned at the top side of the housing, wherein the lock arm of each locking member is offset with respect to the base along a direction perpendicular to the base such that when the locking projection is inserted into the fixing hole from the bottom side of the housing, the base is positioned at the bottom side of the housing and the lock arm is positioned at the top side of the housing.

9. The electrical connector of claim 8, wherein each locking member further comprising a catch member formed at an end portion of the lock arm, the catch member extends from the lock arm along a direction opposite to the locking projection.

10. The electrical connector of claim 9, wherein when the locking projection is positioned in the fixing hole, the locking projection faces the top side of the housing and the catch member is disposed in the cavity and faces the bottom side of the housing.

11. The electrical connector of claim 10, wherein when the circuit board is inserted into the cavity, the catch member engages the circuit board to prevent the detachment of the circuit board from the housing.