A connector

Abstract: To reduce a degree of elastic deformation of a lock arm while securing producing a striking sound at the time of a locking operation. A lock arm (27) includes a locking portion (30) and striking portions (31). The locking portion (30) moves onto a locking projection (13) during a connecting operation of housings (10,20) while engaging the locking projection (13) when the housings are properly connected to prevent the housings (10,20) from separating from each other. The striking portions (31) are formed separately from the locking portion (30) and produce a sound upon striking upon the male housing (10) when the housings (10,20) are properly connected with each other. Since the striking portions (31) for producing a striking sound and the locking portion (30) for locking are separately formed, a vertical dimension of an engaging area of the locking portion (30) with the locking projection (13) can be reduced to suppress a degree of elastic deformation of the lock arm (27) while securely producing the striking sound.

Description: The present invention relates to a connector provided with a locking function. A known connector provided with a locking function is disclosed in Japanese Unexamined Patent Publication No. 6-20740. This connector is constructed, as shown in FIGS. 7 and 8, such that a locking projection 102 is formed on the upper surface of one housing 101 and a lock arm 104 is formed on the upper surface of an other housing 103. The lock arm 104 is so elastically deformed as to move over the locking projection 102 while the housings 101, 103 are being connected. When the housings 101, 103 are properly connected, the lock arm 104 is elastically restored to its original shape and a locking portion 104A provided at its leading end is engaged with the locking projection 102 as shown in FIG. 8, thereby locking the housings 101, 103 into each other. Further, the bottom end of the locking portion 104A strikes upon the upper surface of the mating housing 101 with a sound upon the elastic restoration of the lock arm 104, and this striking sound enables an operator to know that the housings 101, 103 are locked into each other by the lock arm 104. In the above connector, as the height of the locking projection 102 increases, a projecting distance of the locking portion 104A is accordingly lengthened so that that the locking portion 104A can strike upon the upper surface of the mating housing 101. However, as the projecting distance of the locking portion 104A increases, a degree of elastic deformation of the lock arm 104 increases, with the result that a connection resistance resulting from the elastic force of the lock arm 104 disadvantageously increases. US 4,915,643 discloses a connector according to the preamble of claim 1 comprising a female housing and a male housing to be inserted into the female housing. A flexible locking arm having a locking aperture is provided on either the male or female housing, and a locking projection is provided on the respective other housing. The locking projection engages with the locking aperture by the restoring force in the locking arm when the male and female housings are properly fitted together. The connector further comprises a member provided on the locking arm for producing a fitting-confirmation sound by the restoring force in the locking arm when the locking projection becomes engaged with the locking aperture. EP-A-0 821 441 relates to a connector including first and second housings. A lock piece arranged in one housing co-operates with a hooking part on the other housing. A detecting member indicates whether the housings are properly locked together. The present invention was developed in view of the above problem, and an object thereof is to reduce a degree of elastic deformation of a lock arm while maintaining a striking sound which is produced at the time of a locking operation. This object is solved according to the invention by a connector according to claim 1. Preferred embodiments of the invention are subject of the dependent claims. According to a preferred embodiment, the at least one striking portion is formed separately from or in a position different from that of the locking portion. If the striking portion for producing a striking sound and the locking portion for locking are separately formed and since the projecting distance of the locking portion measured starting from the top wall of the locking arm is set smaller than that of the striking portion, a degree of elastic deformation of the lock arm can be decreased to reduce a connection resistance resulting from an elastic force of the lock arm while securely producing a striking sound. Preferably, a pair of striking portions are substantially symmetrically formed with respect to a longitudinal axis of the lock arm. Since the striking portions are symmetrically formed, they do not undergo a twisting deformation at the time of striking. Further preferably, the striking portion is so formed as to be substantially continuous with the locking portion. Since the locking portion is reinforced by forming the striking portion(s) to be continuous therewith, a deformation of the locking portion resulting from a pushing force from the locking projection side when forces act in directions to separate the housings can be securely prevented. According to a further preferred embodiment, the projecting distance of the locking portion is set such that the lock arm interact substantially only with an upper portion, preferably substantially the upper half of the locking projection thereby reducing a degree of inclination or displacement of the lock arm when the locking portion interacts with the locking projection. Accordingly, a connection resistance resulting from the elastic restoring force of the lock arm is reduced. Further preferably, the slider is provided with a flexible wall portion for coming into contact with the lock arm for effecting an unlocking of the lock arm, when the slider is moved to the displacement permitting position when the two housings are locked. Most preferably, the connector further comprises biasing means for biasing the two housings in a disengaging direction with respect to each other. These and other objects and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings in which: FIG. 1A is a section showing a state of a lock arm when female and male housings are separate from each other, and FIG. 1B is a section showing a state of compression coil springs when the housings are separate from each other, FIG. 2A is a section showing a state of the lock arm while the housings are being connected with each other, and FIG. 2B is a section showing a state of the compression coil springs while the housings are being connected with each other, FIG. 3A is a section showing a state of the lock arm when locking by the lock arm is effected, and FIG. 3B is a section showing a state of the compression coil springs when locking by the lock arm is effected, FIG. 4A is a section showing a state of the lock arm when the connection of the housings is completed, and FIG. 4B is a section showing a state of the compression coil springs when the connection of the housings is completed, FIG. 5 is a front view of the female housing, FIG. 6 is a perspective view of the lock arm, FIG. 7 is a section of a prior art connector in its separated state, and FIG. 8 is a section of the prior art connector in its connected state. Hereinafter, a preferred embodiment of the invention is described with reference to FIGS. 1 to 6. A connector according to this embodiment is comprised of a female housing 20 (one housing) provided with one or more female terminal fittings and a slider 32 and a male housing 10 (other housing) provided with one or more male terminal fittings 12. The housings 10, 20 are or can be connected with and separated from each other. In the description of this embodiment, sides of the housings 10, 20 facing each other when they are connected are referred to as front and vertical direction is based on FIGS. 1 to 5. [Male Housing 10] First, the male housing 10 is described. The male housing 10 has a receptacle 11 projecting forward, and the male terminal fittings 12 are at least partly exposed in the receptacle 11 while being arranged substantially side by side. A locking projection 13 is formed preferably in the substantially middle of an upper surface 10A of the male housing 10 with respect to widthwise direction (transverse direction). The front surface of the locking projection 13 serves as a slanted guide surface 13F which is inclined down to the front, whereas the rear surface thereof serves as a locking surface 13R which is slightly inclined with respect to a direction normal to a connecting direction of the housings 10, 20. The locking surface 13R is inclined such that it extends obliquely backward from its bottom end to its upper end, i.e. it overhangs with respect to the upper surface 10A of the male housing 10. Such a locking projection 13 has a substantially triangular cross section when viewed sideways. One pushing portion 14 preferably in the form of a rib extending substantially in parallel with the connecting direction is formed at each of the opposite sides of the locking projection 13. [Female Housing 20] Next, the female housing 20 is described. One or more cavities 21 for at least partly accommodating the one or more female terminal fittings (not shown) are formed substantially side by side inside the female housing 20, and a tubular engaging portion 22 for substantially surrounding a substantially front half of the female housing 20 while being spaced apart therefrom is formed around the female housing 20. The rear end of the female housing 20 is continuous with the outer surface of the rear 20 at its left and right side edges and its bottom edge. Accordingly, a space which penetrates the female housing 20 in longitudinal or forward and backward directions is defined between the upper surface of the female housing 20 and the engaging portion 22. A projecting wall 23 extending substantially backward is preferably so formed as to be continuous with and in flush with the upper surface of the female housing 20. An excessive deformation restricting projection 24 for restricting an excessive deformation of a lock arm 27 to be described later beyond its limit of elasticity is formed on the upper surface of the projecting wall 23. Further, guide walls 25 stand on the opposite side edges of the projecting wall 23, and guide grooves 26 for movably guiding the slider 32 in forward and backward directions are formed in the inner surfaces of the guide walls 25. [Lock Arm 27] The lock arm 27 is integrally or unitarily formed on the upper surface of the female housing 20. The lock arm 27 is comprised of a pair of left and right leg portions 28 standing substantially in middle positions of the female housing 20 with respect to forward and backward directions, and an inclinable displacing portion 29 which is continuous with the upper ends of the leg portions 28 to bridge them and extend forward and backward from the leg portions 28. A portion of the displacing portion 29 before or in front of the leg portions 28 serves as a locking arm portion 29F and a portion thereof behind the leg portions 28 serves as an unlocking arm portion 29R (FIG. 4). In a natural state where no force acts, the displacing portion 29 is held in a position where it extends substantially in parallel to the upper surface of the female housing 20 and the connecting and separating directions of the housings 10, 20, i.e. held in a locking position. While the housings 10, 20 are being connected or separated, the displacing portion 29 is elastically displaced to an unlocking position where the locking arm portion 29F is displaced upward. At the front end of the locking arm portion 29F is formed a locking portion 30 projecting downward along the front edge of the locking arm portion 29F. A striking portion 31 preferably in the form of a substantially narrow rib projects downward from each of left and right edges of the locking arm portion 29F from the front end of 29F up to the leg portions 28. The striking portions 31 are substantially symmetrical with respect to a longitudinal axis (line substantially parallel to the connecting directions of the housings 10, 20) of the displacing portion 29, and the front ends thereof are continuous with the side edges of the locking portion 30. A downward projecting distance or width (along the movement direction of the lock arm 27) W2 of the striking portions 31 is set such that the striking portions 31 can strike upon the upper surface 10A of the male housing 10 when the housings 10, 20 are properly locked into each other by the lock arm 27. A downward projecting distance or width W1 of the locking portion 30 is set shorter than that of the striking portions 31 and is also set such that the locking portion 30 interferes the slanted guide surface 13F of the locking projection 13 while the housings 10, 20 are being connected with each other, and preferably engages substantially an upper half of the locking surface 13R of the locking projection 13 from behind when locking by the lock arm 27 is effected. [Slider 32] The slider 32 is provided in a space between the upper surface of the female housing 20 and the engaging portion 22, and is made movable forward and backward with respect to the female housing 20 by fitting its guidable portions (not shown) provided on the left and right side surfaces into the guide grooves 26. In a displacement permitting position at the front end of a moving path of the slider 32, any further forward movement of the slider 32 is stopped by the contact of the front end of the slider 32 with the inner wall of the engaging portion 22. With the slider 32 located in the displacement permitting position, the deflection or inclining displacement or movement of the lock arm 27 to the unlocking position is permitted since a restricting projection 34 at the front end of the slider 32 is located more forward than the front end of the lock arm 27. The slider 32 in the displacement permitting position is prevented from loosely moving toward a displacement restricting position by an elastic holding piece 35 provided on its lower surface being engaged with a receiving portion 36 of the female housing 20. When the male housing 10 approaches a position where it is properly connected with the female housing 20, the front upper edge of the male housing 10 elastically displaces the elastic holding piece 35 in a disengaging direction from the receiving portion 36. This permits the slider 32 to move to the displacement restricting position. On the other hand, in the displacement restricting position at the rear end of the moving path of the slider 32, any further backward movement of the slider 32 is stopped by the contact of a locking projection 37A on the lower surface of the slider 32 with a stopper 37B of the projecting wall 23 (FIG. 4). With the slider 32 located in the displacement restricting position, the restricting projection 34 is located in such a position as to press or interact with the upper surface of the locking arm portion 29F of the lock arm 27 in the locking position, thereby preventing the lock arm 27 from inclining toward the unlocking position. A flexible wall portion 38 which cantilevers backward and is elastically deformable upward and downward is provided in a center area of the slider 32 with respect to widthwise direction. At the rear end of the flexible wall portion 38 is formed a pushing portion 39 which is substantially in contact with the upper surface of the unlocking arm portion 29R of the lock arm 27 in the locking position when the slider 32 is located in the displacement permitting position. Further, a deformation permitting space 40 for permitting the inclining displacement of the lock arm 27 toward the unlocking position is defined between the flexible wall portion 38 and the upper surface of the lock arm 27. Furthermore, a spring chamber 41 having an open front wall is formed at each of the opposite sides of the deformation permitting space 40 with respect to the widthwise direction of the slider 32. A compression coil spring 42 whose longitudinal axis extends substantially in parallel to longitudinal or forward and backward directions (connecting and separating directions of the housings 10, 20) is accommodated in each spring chamber 41. The rear ends of the coil springs 42 are fixed in the spring chambers 41 by unillustrated locking means, and spring washers 43 are mounted at the front ends of the coil springs 42. The housings 10, 20 are connected with each other as follows. First, the male housing 10 is fitted into the female housing 20 along the inner wall of the engaging portion 22 with the slider 32 held in the displacement permitting position (see FIG. 1). Then, the slanted guide surface 13F of the locking projection 13 substantially comes into contact with the bottom edge of the locking portion 30 of the lock arm 27, and the locking portion 30 slides up on the slanted guide surface 13F. As the locking portion 30 slides up, the lock arm 27 is elastically inclined toward the unlocking position while displacing the locking arm portion 29F upward (see FIG. 2). When the housings 10, 20 are properly connected with each other, the locking portion 30 reaches the top of the locking projection 13 and moves over it, with the result that the locking portion 30 is disengaged from the upper surface of the locking projection 13 and the lock arm 27 is substantially returned to the locking position by moving the locking arm portion 29F down by its elastic restoring force. By this returning movement of the lock arm 27, the locking portion 30 engages the locking surface 13R of the locking projection 13 from behind (see FIG. 3). As a result, the housings 10, 20 are locked into each other. When the lock arm 27 is returned to the locking position, the lower surfaces of the striking portions 31 substantially strike upon or come into contact with the upper surface 10A of the male housing 10 with force due to the elastic restoring force of the lock arm 27, thereby producing a large striking sound. This striking sound enables an operator to know that locking by the lock arm 27 has been effected. While the housings 10, 20 are being connected with each other, the front ends of the pushing portions 14 of the male housing 10 come into contact with the coil springs 42. As the connection progresses, the coil springs 42 are elastically compressed. Immediately before the housings 10, 20 are properly connected with each other, the male housing 10 engages the elastic holding piece 35 to displace it in the disegnaging direction from the receiving portion 36, with the result that the slider 32 is released from a state where its backward movement is prevented by the elastic holding piece 35 and moved backward from the displacement permitting position to the displacement restricting position by biasing forces of the coil springs 42 (see FIG. 4). Consequently, the restricting projection 34 of the slider 32 is brought into contact with the upper surface of the locking arm portion 29F of the lock arm 27 to prevent the lock arm 27 from being inclined toward the unlocking position. In this way, the connecting operation of the housings 10, 20 is completed. In the case that the connecting operation is interrupted before the housings 10, 20 are properly connected with each other, the male housing 10 is pushed out of the male housing 10 by the elastic restoring forces of the coil springs 42 compressed by the pushing portions 14 to be completely separated from the female housing 20. Thus, the housings 10, 20 are not left partly connected. The housings 10, 20 in their properly connected state are separated as follows. The slider 32 in the displacement restricting position is moved forward to the displacement permitting position against the biasing forces of the coil springs 42, and the rear end of the flexible wall portion 38 is pushed down in this position. Then, the pushing portion 39 pushes the unlocking arm portion 29R of the lock arm 27 down, thereby inclining the lock arm 27 to the unlocking position to displace the locking portion 30 up to a position higher than the upper end of the locking projection 13. As a result, unlocking is effected. Then, the elastic restoring forces of the coil springs 42 act on the pushing portions 14 of the male housing 10 to push the male housing 10 out of the female housing 20. As a result, the housings 10, 20 are separated from each other. (1) Since the downward projecting distance or width W1 of the locking portion 30 is set such that the locking portion 30 engages only the substantially upper half of the locking surface 13R of the locking projection 13, a degree of inclining displacement of the lock arm 27 when the locking portion 30 moves over or interacts with the locking projection 13 can be suppressed to a low level. This enables a reduction in connection resistance resulting from the elastic restoring force of the lock arm 27. (2) Since the reduction in the degree of inclining displacement of the lock arm 27 means a reduction in the height of the deformation permitting space 40, the height of the female housing 20 as a whole can be reduced. Further, a vertical stroke of the flexible wall portion 38 upon being pushed and an operational resistance resulting from the elastic restoring force of the lock arm 27 are reduced when locking by the lock arm 27 is released. Thus, an excellent unlocking operability can be provided. (3) The locking portion 30 having its downward projecting distance reduced has no function of producing a sound due to its strike upon the upper surface 10A of the male housing 10. Since the striking portions 31 are formed separately from the locking portion 30 to produce a striking sound in this embodiment, a vertical dimension of the engaging area of the locking portion 30 with the locking projection 13 can be reduced while securely producing a striking sound. (4) If one striking portion 31 is formed only at the left or right side, the lock arm 27 may undergo a twisting deformation at the time of striking. However, since a pair of striking portions 31 are laterally symmetrically formed in this embodiment, this prevents the lock arm 27 from undergoing a twisting deformation at the time of striking. (5) Since the striking portions 31 are preferably continuous with the left and right side edges of the locking portion 30, rigidity of the locking portion 30 against a pushing force acting in forward and backward directions can be enhanced. Accordingly, even if the locking portion 30 is pushed from behind from the side of the locking projection 13 upon the action of a force for separating the housings 10, 20 from each other, deformation of the locking portion 30 is securely prevented, which provides a very reliable locking function. The present invention is not limited to the above embodiments. For example, following embodiments are also embraced by the technical scope of the invention as defined in the claims. Besides these embodiments, various changes can be made without departing from the scope as defined in the claims. (1) Although the pair of striking portions are laterally symmetrically provided in the foregoing embodiment, only either one of them may be formed according to the present invention. (2) Although the striking portions are preferably continuous with the locking portion at their front ends in the foregoing embodiment, the striking portions and the locking portion may be separate according to the present invention. (3) In the foregoing embodiment, the lock arm is of the type which has the locking arm portion and the unlocking arm portion projecting in opposite directions from the leg portions and is displaceable like a seesaw. However, the present invention is also applicable to a lock arm which extend in one direction from the leg portions. LIST OF REFERENCE NUMERALS 10 male housing (other housing) 13 locking projection 20 female housing (one housing) 27 lock arm 30 locking portion 31 striking portion

Claims: A connector, comprising: a pair of housings (20, 10) connectable with each other, a lock arm (27) formed on one of the housings (20), and a locking projection (13) formed on the other of the housings (10), the lock arm (27) moving over the locking projection (13) while being elastically deformed during a connecting operation of the housings (20, 10), and being elastically restored substantially to its original shape to engage the locking projection (13), thereby locking the housings (20, 10) into each other, and a striking sound being produced upon the lock arm (27) striking upon the other housing (10) due to its elastic restoring force when the housings (20, 10) are properly connected with each other, wherein the lock arm (27) comprises: a locking portion (30) for interfering the locking projection (13) and moving thereon during the connecting operation of the housings (20, 10) while engaging the locking projection (13) when the housings (20, 10) are properly connected with each other, and at least one striking portion (31) which is located in such a non-interfering position where it does not interfere the locking projection (13) and adapted to strike upon the other housing (10) when the housings (20, 10) are properly connected with each other, and the projecting distance (W1) of the locking portion (30) measured starting from the top wall of the locking arm along the movement direction of the lock arm (27) is set shorter than that (W2) of the striking portion (31) characterized in that the connector further comprises a slider (32) being movably providable in the one housing (20) for restricting a movement of the lock arm (27), when the slider (32) is positioned in a displacement restricting position, while allowing the movement of the lock arm (27), when the slider (32) is located in a displacement permitting position, the slider (32) comprises a restricting projection (34), which is located in such a position as to interact with the upper surface of the locking arm portion (29F) of the lock arm (27) when the slider (32) is located in the displacement restricting position, and the slider is formed such as to define a deformation permitting space (40) for permitting the displacement of the lock arm (27) in an unlocking direction. A connector according to claim 1, wherein a pair of striking portions (31) are substantially symmetrically formed with respect to a longitudinal axis of the lock arm (27). A connector according to one or more of the preceding claims, wherein the striking portion (31) is so formed as to be continuous with the locking portion (30). A connector according to one or more of the preceding claims, wherein the projecting distance (W1) of the locking portion (30) is set such that the lock arm interacts only with an upper portion, preferably substantially the upper half of the locking projection (13) thereby reducing a degree of inclination of the lock arm (27) when the locking portion interacts with the locking projection (13). A connector according to one or more of the preceding claims, wherein the slider (32) is provided with a flexible wall portion (38) for coming into contact with the lock arm (27) for effecting an unlocking of the lock arm (27), when the slider (32) is moved to the displacement permitting position when the two housings (20, 10) are locked. A connector according to one or more of the preceding claims, further comprising biasing means (42) for biasing the two housings (20, 10) in a disengaging direction with respect to each other.

Inventors: HASEGAWA TERUAKI, KAWASE KIYOTAKA, HASEGAWA, TERUAKI, KAWASE, KIYOTAKA
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 2000
Main classification: H01R13
IPC codes: H01R13