US2500292A - Multipoint electrical connector - Google Patents

Description

March M, 31950 H. MILHENCH ETAL 2,500,292

MULTIPOINT ELECTRICAL CONNECTOR 4 Sheets-Sheet 1 Filed Jan. 10, 1946 INVENTORS HARRY MILHENOH BENJAMEN CEClL GRESTY EDGAR EUGENE COMFORT ATTOR N EY M H Q 1950 H. MlLHE NCH ETAL E fi fi MULTIPQINT ELECTRICAL CONNECTOR Filed Jan. 10, 1 946 4 Sheets-Sheet z FIG/IA I Till/III:

INVENTORS HARRY HENCH BENJAM CECIL GRES EDGAR EUGENE COMFO ATTORNEY M, 19% H. MILHENCH ETAL J 9 MULTIPOINT ELECTRICAL CONNECTOR Filed Jan. 10, 1946 4 Sheets-Sheet s INVENTORS HARRY MILHENOH BENJAMEN CECIL GRESTY EDGAR EUGENE COMFORT ATTORNEY h H950 H. MILHENCH ETA]. 2

MULTIPOINT ELECTRICAL CONNECTOR Filed Jan. 10, 1946 I 4 Sheets-Sheet 4 F1 11 J INVENTORS 'HARRY MILHENOH GRESTY 'BENJAMEN CECIL 51 52 EDGAR EUGENE COMFORT ATTORNEY.

Patented Mar. 14, 1950 UNITED STATES PATENT OFFICE 2,500,292 MULTIPOINT ELECTRICAL CONNECTOR Application January 10, 1946, Serial No. 640,282 In Great Britain February 2, 1945 The present invention relates to multi-point electrical connectors and particularly to equipment of the type in which a plug carried by a piece of electrical apparatus adapted to be removably supported on a rack or the like is arranged automatically to engage a jack on the rack when the piece of apparatus is placed in position. The invention finds particular application to automatic switches, relay sets and the like as used in automatic telephone and similar light current signalling systems. For convenience the component parts of each connector will hereinafter be termed switch plug and shelf jack respectively.

Existing practice is for both switch plugs and shelf jacks to be rigidly mounted in their respective positions, and difiiculty is sometimes experienced in ensuring the necessary accurate alignment therebetween, particularly when difiering pieces of interchangeable electrical apparatus are successively positioned in one mounting location. The chief object of the invention is to enable this alignment problem to be overcome in a simple and ready manner.

According to one feature of the invention, in a multi-point electrical connector arrangement suitable for detachably mounted electrical equipment which is supported independently of the contacts such as automatic switches as used in telephone systems, the contacts forming one of the complementary parts of the connector are secured together to form a rigid unit which is arranged to have appreciable freedom of movement relative to its associated member which defines the mounted position of the equipment.

According to another feature of the invention, in a multi-point electrical connector arrangement suitable for use in connection with the mounting on racks of individual pieces of electrical equipment which are supported independently of the contacts such as automatic switches as used in telephone systems, a plurality of the contacts on the rack associated with one piece of equipment are mounted together to form a rigid unit which is given appreciable freedom of movement relative to the member which supports the piece of equipment so as to facilitate replacement of the piece of equipment on the rack.

A further feature of the invention is that in a multi-point electrical connector arrangement suitable for use in connection with the mounting on racks of individual pieces of electrical equipment which are supported independently of the contacts such as automatic switches as used in telephone systems, a plurality of the contacts 4 Claims. (Cl. 179-91) on an individual piece of equipment are mounted together to form a rigid unit which is given appreciable freedom of movement relative to the member which is supported by the rack so as to facilitate replacement of the piece of equipment on the rack.

The invention will be better understood from the following description of three methods of carrying it into efiect, reference being had to the accompanying drawings comprising Figs. 1 to 11 inclusive in which it is shown applied to automatic switches of the type disclosed in United States Patent No. 2,124,750 issued July 26, 1938, to R. N. Saxby, which are adapted to be accommodated in mounting arrangements of the type disclosed in United States Patent No. 2,067,246 issued January 12, 1937, to R. N. Saxby.

Of the drawings, Fig. 1 shows a side elevation of a movable or self-aligning shelf jack, Fig. 1A shows a plan view of the movable or self-aligning shelf jack looking in the direction E in Fig. 1, Fig. 2 shows a side elevation of a switch cradle member mounted on a shelf, Fig. 2A shows a plan View of the switch cradle member looking in the direction F of Fig. 2, Fig. 3 shows a side elevation of the cradle when equipped with the self-aligning jack, and Fig. 3A shows an enlarged view of a part of the apparatus shown in Fig. 3.

Fig. 4 shows a side elevation of part of a switch cradle member mounted on a shelf and equipped with a pair of shelf jacks, while Fig. 5 shows a side elevation of part of a switch mounting plate equipped with a switch frame and a pair of selfaligning switch plugs which differ from each other in certain details.

Fig. 6 shows a plan view of the upper switch plug in Fig. 5, Fig. 7 shows a sectional view on the line AA in Fig. 6, and Fig. 8 shows an end View looking in the direction B in Fig. 6.

Fig. 9 shows a plan view of the lower switch plug shown in Fig. 5, Fig. 10 shows a sectional elevation on the line CC in Fig. 9, and Fig. 11 shows an end elevation looking in the direction D in Fig. 9.

Referring now to Fig. 2, the cradle member I ll, which is U-shaped and may be of pressed steel, is resiliently mounted on the shelf member it via the intermediary of the rubber pads l2, l3 and M, the free ends of the cradle being linked by the curved bridge piece [5.

The self-aligning shelf jack shown in Figs. 1 and 1A is mounted on the curved bracket l6 and comprises a block I! of ebonite or similar material which is slotted to take the jack contact springs l 8 (only the three left-hand pairs of con tact springs are shown in full). These are insulated from each other by insulating strips 6 and are held in position by an insulating strip [9, metal clamp plate 20 and four countersunk clamping screws which engage in threaded holes in the bracket It.

For the purpose of locating the self-aligning jack on the curved bridge piece l as shown in Fig. 3, two or more tapped holes 5 are provided in the latter to accommodate screws such as 21 which extend through slotted holes 2 in the bracket [6, the height of the holes 2 as seen in Fig. 1A being slightly larger than the largest diameter of the screw 2| so as to allow the screw 2i to pass loosely thru the hole 2. The ends of the screws 2! which engage in the bridge piece I5 are of smaller diameter than the portions extending thru the holes 2 shown in Fig. 3A. These screws are screwed fully home into the tapped holes 5 so that the shoulder portion engages the bridge piece it through the holes 2 in the bracket IS. The nut 23 is then adjusted so as to give suitable play to the bracket and the position is secured by the lock nut 22. It can be seen that the shelf jack mounted in the manner described above will have a limited longitudinal movement on the cradle member, the distance of movement being defined by the length A of the slottedholes 2 in the bracket it.

As an alternative to the screws such as 2| and nuts 22 and 23, use could be made of shouldered screws with the shoulder engaging the bracket I6 instead of passing through the slotted holes 2 therein, the depth or" shoulder would then be such that the shelf jack would be always free to perform slight lateral movement to enable it accurately to align itself with the switch plug of any switch which was jacked in position into the cradle member concerned.

Considering now the embodiments of the invention in which the switch plug is movable rather than the shelf jack or in which both the switch plug and shelf jacks are movable, and referring first to Fig. 4, a pair of shelf jacks have been shown in this illustration in order that consideration may be given to the two difiering types of switch plugs which may be required on switches of the type in question. The lower shelf jack 30 is movably secured to the curved bridge piece 3| of the cradle member 32 in the same manner as the switch jack in Figs. 1, 1A, 2, 2A, 3, and 3A, while the upper shelf jack 33 is fixedly secured .to the base of an inverted U-shaped bracket 34 in a well known manner, the free ends of which are secured to the side members of the cradle 32. Thus it can be seen that shelf jack 30 is selfal-igning while shelf jack 33 is not self-aligning. This arrangement would seldom be used on 'a mounting arrangement, the switch jacks ordinarily being either both self-aligning or both not self-aligning, but is used here as a good illustration of alternate methods of application with self alig-ning switch plugs.

Referring now to Fig. 5, the switch mounting plate 35 is assumed to be equipped with the-switch frame 36 together with two switch plugs, the upper one representing the standard type of plug which is fitted on all kinds of telephone type switching apparatus except where the plug is required to be fitted direct to the frame of aswitch I of the type in question while the lower plug represents the type evolved for fitting direct to the switch frame.

Considering first the upper switch plu and referring to the various views thereof which are shown in Figs. 6, 7, and 8, the plug assembly comprises the usual ebonite block 40, contact springs such as 4| (only the three left-hand pairs of contact springs are shown in full), insulating strip 42 and metal clamp plate 43, the assembly being held together by the four clamping screws 44. In the usual arrangement (not shown) the countersunk clamping screws 44 screw downwardly through the plug bracket 45 into threaded holes in the plate 43, bracket 45 being in turn anchored to the switch mounting plate by means of a tongue 46, Figs. 5 and 6, integral with bracket 45 which engages a slot in the mounting plate 35, the bracket being rigidly fixed thereto by screws such as 41, Fig. 5. To render the plug adjustable in accordance with the invention the heads of the screws 45 are arranged to be countersunk in the block 4! with the screws still threaded into the clamp plate 43 as shown, thereby forming a selfcontained plug assembly. Two or more slots 18, Fig. 6, are provided in the bracket 45 through which extend shouldered screws 46 which pass through the ebonite block 40 and screw into tapped holes in the clamp plate 33. The depth of the shoulder on the screws 49 is such as to permit free lateral movement of the plug relative to the bracket 65 so that it can align itself with the shelf jack springs on the non-self-aligning shelf jack 33 when the switch is jacked into position.

Referring now to the various views of the lower switch plug which are shown in Figs. 9, l0 and 11, the assembly of this plug as a self-contained unit is substantially the same as for the upper plug but the bracket 58 differs in shape from bracket '45 in view of the conditions peculiar to its tment of the switch frame 36, Fig.5. Bracket 50 is of box formation with a downwardly projecting flange portion 5! which carries two holes 52, Fig. 11, to enable it to be secured to the switch frame by screws such as 53, Fig. 5. When the plug is being assembled on to the switch frame, lugs 5S engage suitable slots in the associated switch mounting plate 35. Free lateral movement of the plug is ensured by the shouldered screws 5'! which locate in slots 53 in the bracket 58 and extend through into threaded holes in the plug clamping plate :59. It will be noted that this plug is inverted compared with the upper plug, so as to enable the wiring tags to clear the bracket extension 51. The allowable lateral movement of the self-aligning shelf jack 3t and the lateral movement of the lower switch plug of Fig. 5 permit easy alignment of the contact springs of the plugand jack when the switch is mounted on the frame.

As between either the self-aligning shelf jack or the-self-aligning switch plug method for ensuring accurate alignment between switch plugs and shelf jacks, the use of the self-aligning switch plug offers the advantage that switches, relay sets, and like pieces-of electrical apparatus so equipped will produce automatic alignment between their plugs and the shelf jacks regardless of whether the shelves and associated jacks are new or existing items, that is to say whether the jacks are of the self-aligningor fixed type.

We claim:

1. In a telephone mounting system, a rack, a switch, a multi-contact jack rigidly secured to said rack, a multi-contact plug having contacts corresponding to certain contacts of said jack, openings in said switchpa number of screws equal to the number of openings, each screw smaller in diameter than the opening, means for securing said plug to said switch by said screws thru said openings so as to allow limited movement of the plug relative to the switch, and means for mounting said switch on said rack to cause the plug to engage the jack, said relative movement permitting proper alignment oi? the corresponding contacts of said jack and plug.

2. In a telephone mounting system, a rack, a switch, a multi-contact plug rigidly secured to said switch, a multi-contact jack having contacts corresponding to certain contacts of said plug, openings in said jack, a number of screws equal to the number of openings, each screw smaller in diameter than the opening, means for securing said jack to said rack by said screws thru said openings so as to allow limited movement of the jack relative to the rack, and means for mounting the switch on said rack to cause the plug to engage the jack, said relative movement permitting proper alignment of the corresponding contacts of said jack and plug.

3. In a mounting arrangement, a base, a member, a jack comprising a plurality of contacts mounted on said base, a plug comprising a plurality of contacts corresponding to the contacts of said jack mounted on said member, means for mounting said member on said base to cause said plug contacts to engage said corresponding jack contacts, and means for securing said jack to said base to permit limited movement of said jack relative to said base and for securing said plug to said member to permit limited movement of said plug relative to said member to thereby insure proper alignment of said corresponding jack contacts and plug contacts when said member is mounted on said base.

4. In a mounting arrangement, a base, a member, a multi-contact jack on said base, a multicontact plug on said member having contacts corresponding to the contacts on said jack, means for mounting said member on said base to cause said plug contacts to engage said jack contacts, a first link securing said jack to said base to allow limited movement of said jack relative to said base, and a second link securing said plug to said member to allow limited movement of said plug relative to said member, said relative movements permitting a proper alignment of the corresponding contacts of said plug and jack when said member is mounted on said base.

HARRY MILHENCH. BENJAMIN CECIL GRESTY. EDGAR EUGENE COMFORT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,418,171 Raettig May 30, 1922 1,587,120 Haddock June 1, 1926 1,771,088 Kessler et al July 22, 1930 2,067,246 Saxby Jan. 12, 1937 2,124,750 Saxby July 26, 1938 2,440,270 Hecht Apr. 27, 1948

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