Electrical connector position assurance system

Abstract: A connector position assurance system is provided for an electrical connector (12) adapted for mating with another mateable connecting device (14). The connector includes a housing (48) having a guideway (52,56) and a stop surface (74) near the guideway. A primary flexible locking arm (58) on the housing includes a latch (68) for mechanically interlocking with a cooperating latch (44) of the mateable connecting device. A connector position assurance (CPA) device (16) is slidable along the guideway between a first position allowing movement of the locking arm (58) and mating of the connector (12) with the mateable connecting device (14), and a second position blocking movement of the locking arm away from a latched position. The CPA device (16) includes a flexible stop arm (20) engageable with the stop surface (74) on the housing to prevent the CPA device from moving from its first to its second position. The mateable connecting device (14) includes an actuator (36) for moving the flexible stop arm (20) of the CPA device (16) out of engagement with the stop surface (74) automatically when the connector (12) is fully mated with the mateable connecting device (14), thereby allowing movement of the CPA device (16) from its first position to its second position indicating full mating of the connector.

Description: Field of the Invention This invention generally relates to the art of electrical connectors and, particularly, to a connector position assurance system for an electrical connector adapted to mate with another mateable connecting device. Background of the Invention Electrical connectors normally require secure mechanical and electrical engagement between one electrical connector and a mateable electrical connector or other mateable connecting device. Various latching systems have been used with electrical connectors to provide such secure engagement. Such systems usually provide this secure engagement with ease of attachment and detachment. For instance, latching mechanisms have been developed which include pivotally supported latch arms that interlock with each other or that interlock with a complementary latching mechanism of the mateable connector or connecting device. In addition, connector position assurance devices also are known in the art. Typically, the primary function of such devices is to verify that the connectors are fully mated and latched, i.e. that the latching mechanisms are fully or securely engaged. A secondary function often is to prevent the latching mechanisms from inadvertently unlatching and permitting the connectors to separate. These connector position assurance functions may be accomplished in a variety of ways, but most prior art connector position assurance systems employ a spacer that cannot be inserted into its intended position unless the latching arm is fully engaged, and the latching arm cannot be moved when the spacer is properly positioned. Problems often are encountered with such removable spacers because they may be lost or misplaced. Therefore, in some position assurance systems, the spacers may be preloaded on the connector housing. However, one of the problems with such systems is that, should the preloaded spacer be inadvertently moved to its final locking position before the connectors are mated, mating cannot take place. US- PS 5,330,369 discloses a connector which comprises a pair of connector housings, wherein the connector housings are locked and connected by means of locking members. A detecting spacer locked and connected to one of the pair of connector housings serves to indicate a properly locked connector. The detecting spacer is constructed to be withdrawn when the connector housings are properly coupled with each other. US- PS 5,681,178 discloses an electrical connector assembly having a mateable plughousing and receptacle housing as well as a connector position assurance device for indicating that mateable connector housings have been fully mated together. The connector position assurance device CPA includes a central beam having a central detent thereon with an end section for engaging a front section of the plughousing when the connector position assurance device is in a fully advanced position. The connector position assurance device can be latched to the plughousing in a pre-engagement position for preventing inadvertent withdrawal of the CPA from a plughousing. EP-A-0840398 discloses a connector with a pair of havings and a CPA. A locking arm is set on a fulerum to rotate for latching with a mating housing portion. The CPA is slidable along the locking arm, and movable towards its bloching position when a wedge of the mating housing releases the CPA from a stop edge. To ride over the whole step, the CPA is lifted over it. The present invention is directed to solving these problems and satisfying a need for an improved connector position assurance system. Summary of the Invention An object, therefore, of the invention is to provide a new and improved connector position assurance system for an electrical connector adapted to mate with another mateable connecting device. This object is solved by the features of claim 1. Preferred embodiments are set forth in the dependent claims. In the exemplary embodiment of the invention, an electrical connector includes a housing having a guideway and at least one stop surface near the guideway. A primary flexible locking arm is pivoted on the housing and includes a latch for mechanically interlocking with a cooperating latch of the mateable connecting device. A connector position assurance (CPA) device is slidably mounted on the housing for movement along the guideway between a first position allowing movement of the locking arm and mating of the connector with the mateable connecting device and a second position blocking movement of the locking arm away from a latched position. The CPA device includes a flexible stop arm engageable with the stop surface on the housing to prevent the CPA device from moving from its first to its second position. The mateable connecting device includes an actuator for moving the flexible stop arm of the CPA device out of engagement with the stop surface automatically when the connector is fully mated with the connecting device. Thereby, the CPA device is allowed to move from its first position to its second position indicating full mating of the connector. As disclosed herein, the primary flexible locking arm is pivoted to the housing on a fulcrum between a latch end and a rear end of the locking arm. The guideaway comprises a pair of guide rails between which the CPA device slides, each guide rail including one of the stop surfaces. The CPA device is generally E-shaped to include a pair of outside legs and a center leg. The outside legs comprise a pair of the flexible stop arms engageable with the two stop surfaces of the pair of guide rails. The mateable connecting device includes a pair of actuators for moving the stop arms out of engagement with the stop surfaces. The center leg of the E-shaped CPA device extends from a blocking surface which is movable beneath the rear end of the primary locking arm when the CPA device is in its second position to prevent flexing of the front latch end of the locking arm. Other features of the invention include an enlarged flange on the CPA device for grasping by a user to facilitate manual manipulation of the CPA device and movement thereof between its positions. The center leg of the E-shaped CPA device includes detents engageable with the rear end of the primary locking arm to define the first and second positions of the CPA device. Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. Brief Description of the Drawings The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: FIGURE 1 is a perspective view of a connector assembly embodying the connector position assurance system of the invention; FIGURE 2 is a front perspective view of the CPA device; FIGURE 3 is a rear perspective view of the CPA device; FIGURE 4 is an exploded side elevational view of the CPA device, electrical connector and mateable connecting receptacle; FIGURE 5 is a perspective view of the CPA device removed from the connector; FIGURE 6 is a side elevational view similar to that of Figure 4, with the CPA device in its pre-load position on the connector; FIGURE 7 is a perspective view of the CPA device in the pre-load position; FIGURE 8 is a side elevational view of the connector assembly, partially broken away and in section, to show the flexible stop arms of the CPA device being moved by the actuator posts of the mateable connecting device; and FIGURE 9 is a view similar to that of Figure 8, with the CPA device in its second or blocking position. Detailed Description of the Preferred Embodiment Referring to the drawings in greater detail, and first to Figure 1, the connector position assurance system of the invention is disclosed in an electrical connector assembly, generally designated 10, which includes an electrical connector, generally designated 12, adapted for mating with another mateable connecting device, generally designated 14. A connector position assurance (CPA) device, generally designated 16, is mounted on each opposite side of connector 12 in the direction of arrow "A". Only one of the CPA devices is shown in the drawings. Mateable connecting device 14 is a mateable connecting receptacle structure having a plurality (three) of receptacles 18. Although only one connector 12 is shown in the drawings, one of the connectors is inserted into each receptacle 18 in the direction of arrow "B". Before proceeding with a description of connector 12 and receptacle device 14, reference first is made to Figures 2 and 3 which show CPA device 16. The device is generally E-shaped to define a pair of outside legs 20 and a center leg 22 joined by a cross portion 23 which defines an enlarged flange for grasping by a user to manually manipulate and move the CPA device. Each outside leg 20 includes an outwardly directed latch hook 24 having a forwardly facing angled or chamfered surface 26. The outside legs have blunt distal ends 27. Center leg 22 extends from a central blocking surface 25 and includes a latch hook 28 with an angled or chamfered surface 30, along with a raised boss 32 having chamfered surfaces 34 on opposite sides thereof. As will be seen hereinafter, latch hook 28 and raised boss 32 form detents which define respective positions of the CPA device on connector 12. Referring to Figure 4 in conjunction with Figure 1, mateable connecting device 14 has a pair of actuator posts 36 at opposite sides of a recessed area 38 at each opposite end of each receptacle 18. The connecting device may be a one-piece structure unitarily molded of plastic material or the like. A cut-out wall 40 is located at each opposite end of each receptacle 18 so as to be somewhat flexible in relation to a more rigid side wall 42 of the connecting device. A cooperating latch 44, having a lead-in chamfered surface 46, projects outwardly from each flexible wall 40. As will be seen hereinafter, latches 44 are provided for cooperating with latches on primary locking arms of connectors 12, and actuator posts 36 are provided for activating CPA device 16 so that the CPA device can move to its blocking position. Referring to Figure 5 in conjunction with Figure 1, connector 12 includes a housing 48 of dielectric material for mounting a plurality of terminals (not shown) in respective terminal-receiving cavities or passages 50. The housing may be molded of plastic material or the like. The housing has a guideway defined by a pair of laterally spaced guide rails 52 and a mouth 54 defined by a pair of laterally spaced guide rail flanges 56. A primary flexible locking arm 58 is pivotally mounted on a fulcrum 60 between or intermediate a front latch end 62 of the locking arm and a rear end 64 of the locking arm. A closed slot 66 extends between the opposite ends of the locking arm to define a front latch shoulder 68 and a rear positioning shoulder 70. Each guide rail 52 has an aperture 72 defining a stop surface 74. In Figures 1, 4 and 5, CPA device 16 is shown removed from connector 12, but the CPA device is mountable on its respective end of the connector housing 48 in the direction of arrows "A" until the CPA device is in its first or pre-load position shown in Figures 6 and 7. More particularly, in the pre-load position shown in Figures 6 and 7, CPA device 16 has been moved through mouth 54 and slidably between guide rail flanges 56 and guide rails 52. Outside legs 20 (Figs. 2 and 3) of the CPA device define flexible stop arms thereof. When the CPA device is inserted into mouth 54, chamfered leading surfaces 26 of latch hooks 24 engage the inside corners of guide rail flanges 56 to flex stop arms 20 inwardly until the latch hooks become aligned with apertures 72 in guide rails 58. The stop arms snap back outwardly as latch hooks 24 snap into apertures 72. This defines the pre-load position of CPA device 16. In the pre-load position, the CPA device cannot back out of mouth 54 because of the interengagement of latch hooks 24 with the bottom ends 56a of guide rail flanges 56 as clearly shown in Figure 7. In addition, abrupt distal ends 27 (Figs. 2 and 3) of flexible stop arms 20 engage stop surfaces 74 defined by apertures 72. This prevents the CPA device from being moved inwardly beyond its pre-load position. In other words, when latch hooks 24 snap into apertures 72 in guide rails 52, the CPA device cannot move either in or out of its pre-load position. When in the pre-load position of the CPA device as best shown in Figure 7, rear end 64 of primary locking arm 58 is disposed between latch hook 28 and raised boss 32 of center leg 22 of the CPA device. This allows free pivoting movement of primary locking arm 52 about fulcrum 60. In other words, either opposite end 62 or 64 of the primary locking arm can "teeter" about fulcrum 60 when the CPA device is in its pre-load position. Figure 8 shows connector 12 and CPA device 16 being moved further into its respective receptacle 18 (Fig. 1) of mateable connecting device 14 in the direction of arrow "B". When connector 12 is inserted into its respective receptacle 18 in mateable connecting device 14, and with CPA device 16 in its pre-load position, front latch end 62 of primary locking arm 52 snaps into mechanical interlocking engagement with cooperating latch 44 on the mateable connecting device. As the connector is inserted into its respective receptacle, it can be seen in Figure 8 that actuator posts 36 engage chamfered surfaces 26 of latch hooks 24 which project outwardly from stop arms 20 of the CPA device. This causes the stop arms to be biased inwardly in the direction of arrows "D". When the latch hooks are biased inwardly, the latch hooks clear apertures 72 (Fig. 7) in guide rails 58, allowing the CPA device to move in the direction of arrow "E" (Fig. 9) to a second position blocking movement of primary locking arm 58 from its latched position. In the second or blocking position of CPA device 16 as shown in Figure 9, flexible stop arms 20 snap back outwardly in the direction of arrows "F" until latch hooks 24 lockingly engage behind shoulders 80 of mateable connecting device 14. Latch hook 28a of center leg 22 of the CPA device also is disposed on the inside of rear end 64 of the primary locking arm. In this blocking position of the CPA device, raised boss 32 (Fig. 2) moves past rear end 64 of primary locking arm 58 whereby blocking surface 25 is positioned just behind rear end 64 which, in turn, prevents any pivoting movement of the locking arm about fulcrum 60. Therefore, with the CPA device in the position of Figure 9, the primary locking arm is immobilized and completely blocked from unlatching movement away from complementary latch 44 of mateable connecting device 14. The connector can be unmated only by applying a force, in a direction opposite arrow "A" (Fig. 5), to the CPA device at cross portion 23 to push raised boss 32 past rear end 64 and move the CPA device back to its pre-load position. In that position, front latch end 62 of primary locking arm 52 can be moved out of interlocking with latch 44 on the mateable connecting device by pushing in on rear end 64 of the locking arm, whereupon the connector can be pulled out of its receptacle 18 in the mateable connecting device. It will be understood that the invention may be embodied in other specific forms without departing from the characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.

Claims: A connector position assurance system for an electrical connector (12) adapted for mating with another mateable connecting device (14), comprising: said connector (12) including a housing (48) having a guideway (52,56) and at least one stop surface (74) near the guideway; a primary flexible locking arm (58) on the housing and including a latch (68) for mechanically interlocking with a cooperating latch (44) of the mateable connecting device (14); wherein said primary flexible locking arm (58)is pivoted to the housing (48) on a fulcrum (60) between a front latch end(62) and a rear end (64) of the locking arm, a connector position assurance (CPA) device (16) slidably mounted on the housing for movement along said guideway (52,56) between a first position allowing movement of the locking arm (58) and mating of the connector (12) with the mateable connecting device (14) and a second position blocking movement of the locking arm (58) away from a latched position, the CPA device (16) including a flexible stop arm (20) engageable with the stop surface (74) on the housing to prevent the CPA device from moving from its first to its second position caracterised by detents of the CPA device (16) (32,28) engageable with the rear end (64) of the locking arm (58) to define the first and second positions of the CPA device (16); whereby said mateable connecting device (14) includes an actuator (36) for moving the flexible stop arm (20) of the CPA device (16) out of engagement with said stop surface (74) automatically when the connector is fully mated with the mateable connecting device thereby allowing movement of the CPA device (16) from its first position to its second position indicating full mating of the connector. The connector position assurance system of claim 1 wherein said primary flexible locking arm (58) is pivoted to the housing (48) on a fulcrum (60) between a front latch end (62) and a rear end (64) of the locking arm, and the CPA device (16) includes a blocking portion (32) moveable beneath the rear end (64) of the locking arm (58) when the CPA device is in its second position to prevent flexing of the front latch end (62) of the locking arm. The connector position assurance system of claim 1 wherein said guideway comprises a pair of guide rails (52) between which the CPA device (16) slides. The connector position assurance system of claim 3 wherein each of said guide rails (52) includes one of said stop surfaces (74), the CPA device (16) includes a pair of said flexible stop arms (52) engageable with the stop surfaces, and the mateable connecting device (14) includes a pair of said actuators (36) for moving the stop arms (20) out of engagement with the stop surfaces. The connector position assurance system of claim 1 wherein said CPA device (16) includes an enlarged flange (24) for grasping by a user to facilitate manual manipulation of the CPA device.

Inventors: HIGGINS MICHAEL PATRICK, MOON CLARENCE ROBERT III, PILL ANTHONY J, HIGGINS, MICHAEL PATRICK, MOON, CLARENCE ROBERT III, PILL, ANTHONY J.
Applicants: MOLEX INC, MOLEX INCORPORATED
Application year: 1999
Main classification: H01R13
IPC codes: H01R13, H01R11