Apparatus for positively preventing misengagement of multipoint connector elements

Abstract: An apparatus ( 10 ) for positively preventing misengagement of multipoint connector elements includes a mounting rack ( 26 ) having a pivot slot ( 18 ) and a stepped guide surface ( 32 ), along with an associated receptacle element ( 34 ) of a multipoint connector. The apparatus ( 10 ) also includes a housing ( 44 ) having a pivot pin ( 20 ) and a stepped guide surface ( 50 ), along with an associated plug element ( 54 ) of multipoint connector. Only when the pivot pin ( 20 ) is fully seated in the pivot slot ( 18 ) will the receptacle ( 34 ) and plug ( 54 ) elements be able to engage. Otherwise, the stepped guide surfaces ( 32, 50 ) act to positively prevent such engagement. Also, the stepped guide surfaces ( 32, 50 ) are concentrically mated to provide angular engagement and disengagement paths that result in a plurality of plug pin contacts ( 68 ) and receptacle socket contacts ( 70 ) engaging and disengaging in a sequential order, respectively.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to methods for insuring that multipoint connector elements are properly aligned and engaged and, more particularly, to an apparatus for positively preventing misengagement of multipoint connector elements when they are not properly aligned. Description of the Prior Art The use of multipoint connectors is well known in the art of electrical connection. Such use allows a plurality of electrical signals to be transmitted from a conventional male-type element, or plug, of a multipoint connector to a conventional female-type element, or receptacle, of a multipoint connector, and vice versa . Of course, for these electrical signal transmissions to occur, the plug and receptacle elements of the multipoint connector must be properly aligned and engaged. Several prior art techniques have been used to positively insure proper alignment and subsequent proper engagement of multipoint connectors. For example, U.S. Patent No. 4,257,665, describes a technique where a receptacle element of a multipoint connector provides a projecting arm having a curved pivot surface that fits into an aperture formed in a corresponding plug element. When inserted through the aperture, the projecting arm guides a pivot movement between the receptacle and the plug elements to positively insure a proper alignment and engagement. Also, in U.S. Patent No. 3,668,605, a technique is described where a plug element of a multipoint connector provides a pivot pin and an alignment tongue that fit into a pair of alignment slots and an opening, respectively, provided by a corresponding receptacle element. The angle of the alignment tongue when inserted through the opening is such to cause the pivot pin to be firmly seated in the alignment slots, thereby positively insuring a proper alignment and engagement of the connector elements. Although both of the above-mentioned patents describe valid techniques for positively insuring proper alignment and subsequent proper engagement of multipoint connector elements, neither describes a technique for positively preventing misengagement of multipoint connector elements when they are not properly aligned. Such positive prevention is addressed by the present invention described herein. SUMMARY OF THE INVENTION The present invention contemplates a apparatus for positively preventing misengagement of multipoint connector elements when they are not properly aligned. Such positive prevention is realized by combining a pivot action, similar to that described in the prior art, with two pairs of unique mating concentric guide surfaces that act to stop the pivot action, and hence a engagement of the multipoint connector elements, when the multipoint connector elements are not properly aligned. The mating concentric guide surfaces are unique in that they are stepped, thereby causing the pivot action of the connector elements to be stopped by opposing steps when the connector elements are not properly aligned. Both pairs of unique mating concentric guide surfaces are formed in a similar manner, wherein a first stepped concentric guide surface is formed in a housing structure that has a associated plug-type connector element, and a second stepped concentric guide surface is formed in a mounting structure that has an associated receptacle-type connector element. The housing structure also provides a pair of pivot pins, while the mounting structure also provides a corresponding pair of pivot slots. Thus, the pivot action between the plug element and the receptacle element, or the housing structure and the mounting structure, respectively, is dictated by seating the pivot pins within the pivot slots. However, only when the pivot pins are fully seated within the pivot slots will the steps of the unique mating concentric guide surfaces allow engagement of the connector elements, thereby positively preventing misengagement until proper alignment is obtained. Accordingly, the primary objective of the present invention is to provide a simple and effective means for positively preventing misengagement of multipoint connector elements when they are not properly aligned. Another objective of the present invention is to provide a means for sequentially engaging and disengaging electrical contacts in multipoint connector elements. Other objectives and advantages of the present invention will become apparent to those skilled in the art from the following detailed description read in conjunction with the appended claims and the drawings attached hereto. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a portion of a modular programmable logic controller (PLC) system incorporating the present invention concept for positively preventing misengagement of multipoint connector elements when they are not properly aligned. Figure 2 is an exploded perspective view of a mounting assembly corresponding to the modular PLC system described in Figure 1. Figure 3 is a front view of a mounting rail taken along line 3-3 of Figure 2. Figure 4 is a cross-sectional side view of a mounting rail taken along line 4-4 of Figure 3. Figure 5 is an exploded perspective view of a PLC module corresponding to the modular PLC system described in Figure 1. Figure 6A is a side view of a PLC module housing taken along line 6A-6A of Figure 6B. Figure 6B is a front view of a PLC module housing taken along line 6B-6B of Figure 6A or line 6B-6B of Figure 6C. Figure 6C is a side view of a PLC module housing taken along line 6C-6C of Figure 6B. Figure 7A is a side view of a PLC module printed circuit board assembly taken along line 7A-7A of Figure 7B. Figure 7B is a front view of a PLC module printed circuit board assembly taken along line 7B-7B of Figure 7A or line 7B-7B of Figure 7C. Figure 7C is a side view of a PLC module printed circuit board assembly taken along line 7C-7C of Figure 7B. Figures 8A through 8K show a succession of steps detailing the correct procedure for properly aligning and engaging multipoint connector elements according to the present invention. Figure 8L shows one situation where misengagement of multipoint connector elements are positively prevented according to the present invention. PREFERRED EMBODIMENT OF THE PRESENT INVENTION Referring to Figure 1, there is shown a portion 10 of a modular programmable logic controller (PLC) system to illustrate one practical use of the present invention concept to be described herein. The portion 10 of the PLC system shown can be broken down into a mounting assembly 12 and three PLC modules 14, 14', 14". In general, the mounting assembly 12 is stationary and it supports the three portable PLC modules 14 , 14' , 14'' which are portable. The mounting assembly 12 is also capable of supporting three additional PLC modules in the three spare areas 16 , 16' , 16'' to the right of the three PLC modules 14 , 14' , 14'' shown. However, these additional PLC modules are not shown for purposes of figure clarity. The three PLC modules 14 , 14' , 14'' are supported by the mounting assembly 12 through a simple pivot pin and pivot slot arrangement. Each PLC module 14 , 14' , 14 " has two associated pivot pins 20 and the mounting assembly 12 provides a number of pivot slots 18 , 18' , each of which supports at least one of the PLC module pivot pins 20 . Thus, the pivot slots 18 , 18' of the mounting assembly 12 support the pivot pins 20 of the PLC modules 14 , 14' , 14 ", and hence the PLC modules 14 , 14' , 14" themselves. It should be noted that the outer pivot slots 18' provide approximately one half the slot area that the inner pivot slots 18 provide since these outer pivot slots 18' are only required to support a single pivot pin 20 . The simple pivot pin 20 and pivot slot 18 , 18' arrangement is enhanced, according to the present invention, by mating concentric guide surfaces 22 that are formed between the PLC modules 14 , 14' , 14" and the mounting assembly 12 . As will be soon described in more detail, the combination of the pivot pins 20 and pivot slots 18 , 18' arrangement and the mating concentric guide surfaces 22 acts to positively prevent misengagement of multipoint connector elements when they are not properly aligned. Referring to Figure 2, there is shown an exploded view of the mounting assembly 12 described in Figure 1. The mounting assembly 12 is comprised of a backplate 24 , a mounting rail 26 , a backplane printed circuit board 28 , and some miscellaneous mounting hardware 30 . The mounting rail 26 provides the pivot slots 18 , 18' for supporting the PLC modules 14 , 14' , 14" , as described in Figure 1. Associated with each of the pivot slots 18 , 18' is a stepped guide surface 32 which, when mated with one of the previously described corresponding stepped guide surfaces associated with one of the PLC modules 14 , 14' , 14" , forms one of the present invention mating concentric guide surfaces 22 . The backplane printed circuit board 28 is secured to the mounting rail 26 , and hence to the backplate 24 , by the miscellaneous mounting hardware 30 . Associated with the backplane printed circuit board 28 are a number of receptacle-type elements 34 of multipoint connectors. These receptacle elements 34 are positioned on the backplane printed circuit board 28 such that there is one receptacle element 34 located between each adjacent pivot slot 18 , 18' and stepped guide surface 32 extrusion when the mounting assembly 12 is fully assembled. Thus, each receptacle element 34 is positioned in a location where a PLC module 14 , 14' , 14" may be positioned. Accordingly, as will be shown shortly, each of these receptacle elements 34 may mate with a corresponding plug-type element associated with one of the previously described PLC modules 14 , 14' , 14" , if the PLC modules 14 , 14' , 14'' are properly aligned. Referring to Figure 3, there is shown a front view of the mounting rail 26 . Figure 4 is a cross-sectional view of the mounting rail shown in Figure 3 with detail given to the pivot slots 18 , 18' and the stepped guide surfaces 32 . Also shown in Figure 4 is a support bracket 36 that further secures the mounting rail to the backplate 24 through a corresponding support opening 38 , as shown in Figure 2. Referring to Figure 5, there is shown an exploded view of one type 14 of the PLC modules 14 , 14' , 14" shown in Figure 1. This input/output (I/O) type 14 of PLC module is comprised of a front door panel 40 , an I/O connector 42 , a housing 44 , an I/O printed circuit board assembly 46 , and a rear panel 48 . The housing 44 provides the pivot pins 20 that are supported by the mounting rail pivot slots 18 , 18' as described in Figure 1. Associated with each pivot pin 20 is a stepped guide surface 50 which, when mated with one of the previously described corresponding stepped guide surfaces 32 associated with one of the pivot slots 18 , 18' , forms one of the present invention mating concentric guide surfaces 22 . Referring to Figures 6A, 6B and 6C, the housing 44 is shown with detail given to the pivot pins 20 and the stepped guide surfaces 50 . Referring back to Figure 5, the I/O printed circuit board assembly 46 is secured within the housing 44 by the rear panel 48 when the module 14 is fully assembled. Thus, access to the I/O printed circuit board assembly 46 , when it is secured in the housing 44 , can only be obtained through the I/O connector 42 , upon opening the front door panel 40 , or through an opening 52 in the rear panel 48 . This rear panel opening 52 provides access to the I/O printed circuit board assembly 46 by way of a plug-type element 54 of a multipoint connector, which is shown in Figures 7A and 7B. Referring to Figures 7A, 7B, and 7C, there is shown the I/O printed circuit board assembly 46 comprising a printed circuit board 56 having a plurality of electrical finger contacts 58 that connect with the previously described I/O connector 42 , a ground clip 60 , an LED display module 62 , and the plug-type multipoint connector element 54 . The plug element 54 is positioned on the printed circuit board 56 such that its internal pin contacts are facing out through the opening 52 in the rear panel 48 shown in Figure 5. It should be noted that the shaded regions 64 on the printed circuit board 56 indicate areas where components are not allowed to be mounted. The preceding figures and written description detail, among other things, the mounting assembly 12 having the pivot slots 18 , 18' and the stepped guide surfaces 32 , and the I/O type of PLC module 14 having the pivot pins 20 and the corresponding stepped guide surfaces 50 . The mounting assembly also has its associated receptacle multipoint connector element 34 , while the PLC module 14 has its associated plug multipoint connector element 54 . It should be noted, however, that the present invention is not dictated by what type of multipoint connector element is associated with either the mounting assembly 12 or the PLC module 14 . Referring to Figures 8A through 8K, there is shown a succession of steps detailing the correct procedure for properly aligning and engaging multipoint connector elements according to the present invention. Referring specifically to Figure 8A, a cutaway portion of a mounting rail 26 is shown having a pivot slot 18 and a stepped guide surface 32 , along with an associated receptacle-type multipoint connector element 34 . Also shown is a cutaway portion of a PLC module housing 44 having a pivot pin 20 and a stepped guide surface 50 , along with an associated plug-type multipoint connector element 54. Following the succession of steps through from Figure 8A until Figure 8E, the pivot pin 20 proceeds horizontally along a lip 66 of the mounting rail 26 until the steps of each stepped guide surface 32 , 50 are abutted against each other. At this point, the connector elements 34 , 54 are prohibited from engaging since they are not properly aligned. Hence, they are positively prevented from engaging due to their misalignment. Proper alignment and subsequent engagement can be obtained, however, by rocking the PLC module housing 44 radially outward along where the stepped guide surfaces 32, 50 are contacted until the pivot pin 20 is fully seated within the pivot slot 18 . The sequence of steps detailing these radial seating adjustments are shown from Figure 8E to Figure 8I. Referring specifically to Figure 8I, the pivot pin 20 is shown fully seated within the pivot slot 18 and the steps of each stepped guide surface 32 , 50 are no longer abutted against each other so as to prohibit the engagement of the connector elements 34 , 54 . Thus, the connector elements 34 , 54 are now free to be engaged by following an angular engagement approach that is dictated by the concentricity of the stepped guide surfaces 32 , 50 . This angular engagement approach is detailed in the succession of steps shown in Figures 8I through 8K, whereby Figure 8K shows the connector elements 34 , 54 to be fully engaged. Figure 8L is provided to show another scenario wherein the present invention also acts to positively prevent the misengagement of the multipoint connector elements 34 , 54 due to their misalignment. It should be noted that the angular engagement approach detailed in Figures 81 through 8K provides a supplemental benefit to the present invention method of positively preventing misengagement of multipoint connector elements. This supplemental benefit is that, due to the angular engagement approach between the plug multipoint connector element 54 and the receptacle multipoint connector element 34 , electrical contact is made between the pins 68 of the plug element 54 and the sockets 70 of the receptacle element 34 in a sequential order, whereby the pins 68 and the sockets 70 closest to the pivot pin 20 and the pivot slot 18 arrangement are electrically contacted first. This electrical contact sequence is shown in Figures 81, where electrical contact is made between a single pin and socket pair 72 , through Figure 8K, where electrical contact is made between all pin and socket pairs. Such an electrical contact sequence is a benefit since it is often desirable to transmit or receive certain electrical signals prior to others. It should be further noted that the present invention also provides a similar supplemental benefit in that electrical contact is broken between the pins 68 of the plug element 54 and the sockets 70 of the receptacle element 34 in a sequential order when the multipoint connector elements 34 , 54 are disengaged. Similarly, such a broken electrical contact sequence is a benefit since it is often desirable to transmit or receive certain electrical signals after electrical contact has been broken with others. The supplemental benefits of both the electrical contact sequence and the broken electrical contact sequence are affirmatively provided by the present invention. It is thus seen that the objectives set forth above are efficiently obtained and, since certain changes may be made in the above described apparatus without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims: An apparatus for positively preventing misengagement of multipoint connector elements, said apparatus comprising: a plug element (54) of a multipoint connector; a receptacle element (34) of a multipoint connector, wherein said plug element (54) and said receptacle element (34) can be engaged when properly aligned; first alignment means associated with said multipoint connector elements (54, 34) for providing engagement alignment between said plug element (54) and said receptacle element (34), second alignment means associated with said multipoint connector elements (54, 34) for providing engagement alignment between said plug element (54) and said receptacle element (34), characterised in that: said first alignment means includes at least one pivot pin (20) having an associated stepped guide surface (50); and in that said second alignment means includes at least one pivot slot (18) having an associated stepped guide surface (32), the arrangement being such that each said stepped guide surface (50) associated with a respective one of said pivot pins (20) is able to be concentrically mated with a corresponding stepped guide surface (50) associated with a corresponding one of said pivot slots (18), so as to positively prevent misengagement of said multipoint connector elements (54, 34) unless said pivot pin (20) is fully seated in said pivot slot (18) thus ensuring said multipoint connector elements are properly aligned. Apparatus as claimed in claim 1, characterised in that each said stepped guide surface (50) associated with a respective one of said pivot pins (20) has an associated step, in that each said stepped guide surface (32) associated with a respective one of said pivot slots (18) has an associated step, and in that said concentrically matable stepped guide surfaces (32, 50) are adapted to act to positively prevent misengagement of said multipoint connector elements (54, 34) by having said steps abut against each other. Apparatus as claimed in claim 1 or claim 2, characterised in that said concentrically matable stepped guide surfaces (32, 50) provide said multipoint connector elements with an angular engagement path when said pivot pin (20) is fully seated in said pivot slot (18). Apparatus as claimed in claim 3, characterised in that said plug element (54) has a plurality of pin contacts (68), in that each receptacle element (34) has a like plurality of socket contacts (70), and in that said angular engagement path allows electrical contact between said pin contacts (68) and said socket contacts (70) in sequential order. Apparatus as claimed in any preceding claim, characterised in that said concentrically matable stepped guide surfaces (32, 50) provide said multipoint connector elements (54, 34) with an angular disengagement path when said pivot pin (20) is fully seated in said pivot slot (18). Apparatus as claimed in any preceding claim, characterised in that said plug element (54) has a plurality of pin contacts (68), in that said receptacle element (34) has a like plurality of socket contacts (70), and in that said angular disengagement path allows electrical contact to be broken between said pin contacts (68) and said socket contacts (70) in sequential order. Apparatus as claimed in any preceding claim, characterised in that said first alignment means comprises a housing (44) dimensioned for mounting one of said multipoint connector elements (54), and in that said housing (44) provides two pivot pins (20) for the first alignment means and two associated stepped guide surfaces (50) for two pivot slots (18) of the second alignment means. Apparatus as claimed in claim 7, characterised in that said housing (44) is supported by said second alignment means. Apparatus as claimed in claim 7 or claim 8, characterised in that said housing (44) is dimensioned for mounting said plug element (54). Apparatus as claimed in claim 7, claim 8 or claim 9, characterised in that said housing (44) is dimensioned for mounting said receptacle element (34). Apparatus as claimed in any preceding claim, characterised in that said second alignment means comprises a mounting assembly (12) that maintains one of said multipoint connector elements (34), and in that said mounting assembly (12) provides two pivot slots for the first alignment means and two associated stepped guide surfaces for two pivot slots (18) of the second alignment means. Apparatus as claimed in claim 11, characterised in that said mounting assembly (12) supports said first alignment means. Apparatus as claimed in claim 11 or claim 12, characterised in that said mounting assembly (12) maintains said receptacle element (34). Apparatus as claimed in claim 11, claim 12 or claim 13, characterised in that said mounting assembly (12) maintains said plug element (54). A modular programmable logic controller (PLC) system (10) having a mounting assembly (12) and an PLC module (14), wherein said mounting assembly has an associated receptacle element (34) ofa multipoint connector and said PLC module has an associated plug element (54) of a multipoint connector, and wherein said mounting assembly (12) and said PLC module (14) are formed to interact in a manner that positively prevents misengagement of said multipoint connector elements (34, 54), characterised in that: said mounting assembly (12) has a pivot slot (18) with an associated stepped guide surface (32), said mounting assembly also has an associated receptacle element (34) of a multipoint connector; and in that the PLC module (14) has a pivot pin (20) with an associated stepped guide surface (50), said PLC module also has an associated plug element (54) of a multipoint connector, such that said pivot slot (18) and said stepped guide surface (32) of said mounting assembly (12) corresponds with said pivot pin (20) and said stepped guide surface (50) of said PLC module (14) so as to positively prevent misengagement of said multipoint connector elements (34, 54). A system as claimed in claim 15, characterised in that each said stepped guide surface (50) associated with a respective one of said pivot pins (20) has an associated step, in that each said stepped guide surface (32) associated with a respective one of said pivot slots (18) has an associated step, and in that said pivot slot (18) and said stepped guide surface (32) of said mounting assembly correspond with said pivot pin (20) and said stepped guide surface (50) of said PLC module by having said steps abut against each other prior to engagement of said multipoint connector elements (34, 54) unless said pivot pin (20) is fully seated in said pivot slot (18). A system as claimed in claim 15 or claim 16, characterised in that said stepped guide surfaces (32, 50) are able to be concentrically mated to provide said multipoint connector elements (34, 54) with an angular engagement path when said pivot pin (20) is fully seated in said pivot slot (18). A system as claimed in claim 15, claim 16 or claim 17, characterised in that said plug element (54) has a plurality of pin contacts (68), in that said receptacle element (34) has a like plurality of socket contacts (70), and in that said angular engagement path allows electrical contact between said pin contacts (68) and said socket contacts (70) in a sequential order. A system as claimed in any one of claims 15 to 18, characterised in that said stepped guide surfaces (32, 50) are able to be concentrically mated to provide said multipoint connector elements (34, 54) with an angular disengagement path when said pivot pin (20) is fully seated in said pivot slot (18). A system as claimed in any one of claims 15 to 19, characterised in that said plug element (54) has a plurality of pin contacts (68), in that said receptacle element (34) has a like plurality of socket contacts (70), and in that said angular disengagement path allows electrical contact to be broken between said pin contacts (68) and said socket contacts (70) in a sequential order.

Inventors: PARDO LAWRENCE, ST GERMAIN RONALD E, PARDO, LAWRENCE, ST. GERMAIN, RONALD E.
Applicants: SCHNEIDER AUTOMATION, SCHNEIDER AUTOMATION INC.
Application year: 1993
Main classification: H01R13
IPC codes: H01R13, H05K7