US3863044A

US3863044A - Open contact matrix switch

Info

Publication number: US3863044A
Application number: US380432A
Authority: US
Inventors: Maurice D Mccormick
Original assignee: GTE Automatic Electric Laboratories Inc
Current assignee: AG Communication Systems Corp
Priority date: 1973-07-18
Filing date: 1973-07-18
Publication date: 1975-01-28
Anticipated expiration: 1992-01-28
Also published as: CA998197A

Abstract

An open contact matrix is disclosed having a printed wiring card as one of the basic elements thereof; the printed wiring card includes a plurality of fixed contacts and a corresponding plurality of movable contacts extending from the wiring card. A frame is provided for supporting an array of operating members, which are solenoid driven, for selectively moving an actuator above predetermined sets of movable contacts to close them on to their corresponding fixed contacts.

Description

United States Patent 1 1 1111 3,863,044 McCormick 1 Jan. 28, 1975 [54] OPEN CONTACT MATRIX SWITCH 3,397,371 8/1968 Barnaby et al..., 335/112 $445,795 5/1969 Holtfreter et ul. 335/1 I2 [751 Invent Mccmm'ckch'cag 3,529,113 9/1970 Vazquez et al. 335/112 x "l 3.551631 12/1970 Vazquez et al. 200/175 3.662.301 5 1972 335/112 [731 d 3678,422 7/1972 Reimer 335/112 Northlake, lll. I Primary Examiner-James R. Scott Flledl 3 J y 1 1973 Attorney, Agent, or FirmDavid W. Heid [21] Appl. No.: 380,432

Y [57] ABSTRACT [52] US CL 200/175 200/] R 335/112 An open contact matrix is disclosed'having a printed [51] Int. Cl.. 0 01h 6 Holh 67/26 wiring card as one of the basic elements thereoflthe of I I I I I l l n 1 printed Wiring Catd lnClUdeS' a of fixed 200/177 "v" A 1 6 f contacts and a corresponding plurality of movable 335/106 l l3 contacts extending from the wiring card. A frame is provided for supporting an array of operating mem- [56] Refetences Cited bers, which are solenoid driven, for selectively moving an actuator above predetermined sets of movable v UNITED STATES PATENTS contacts to close them on to their corresponding fixed 2,516.772 7/1950 Hickman 335/113 x contacts, 2942.068 6/1960 McCarthy eta]... 200/175 3,157,753 ll/l964 K1866 200/13 11 Claims, 14 Drawing Flgures PAIEM m2 8 1975 saw 2 OF 4 OPEN CONTACT MATRIX SWITCH BACKGROUND OF THE INVENTION This invention relates generally to a matrix arrangement for closing predetermined sets of contacts arranged in a cross coordinate array. In particular, the invention is directed to a cross coordinate switch useful in connecting speech paths in a telephone switching system. Switches of the type disclosed herein are sometimes commonly referred to as crossbar switches, and perform a switching function in the modern automatic telephone switching systems.

Some of the earlier crosspoint switches, such as that disclosed in US. Pat. No. 3,445,795 issued May 20, 1969 to Holtfreter et al., employed an arrangement of select units and hold units, and to keep the selected crosspoint closed it is necessary to maintain current flow through the hold magnet assembly. It is undesirable in modern switching systems to require that a holding current for each crosspoint be maintained during the connection. A more preferable switching technique is to provide crosspoint switches in which a voltage pulse or pulses are used to close or open the cross points.

With this in mind, several crosspoint switches have been devised in which no holding current is required; merely a series of pulses are used to actuate the crosspoint and it maintains its actuated condition until further pulses are used to break down the connection. Crossbar switches illustrative of this type of contact actuation and release are illustrated in, for example, US. Pat. No. 3,529,113 issued to Vazquez et al on Sept. 15, 1970. In this crossbar switch arrangement tightly wound coil springs are used to provide connection at selected crosspoints. A somewhat similar crossbar switch which employs a pulsed connection and release arrangement is shown in US. Pat. No. 3,643,053 issued to Grundig on Feb. 15, 1972. In the Vazquez patent the mobile contact member which is being moved into engagement with the stretched spring, is also a coiled spring which extends upward from the printed circuit board. During the operation and release of the crosspoint in the Vazquez arrangements, the coils of the associated mobile contact element tend to wear the select and connect bars during the operation and release since the spring is moving across the select and connect bar during the connection and release. This problem has been recognized and in the US. Pat. No. 3,551,631, issued to Vazquez et al. on Dec. 29, 1970, an L-shaped opening is included in the switch in an attempt to reduce the wear of the driving teeth of the connection bar which would occur if the mobile contact were allowed to return to its release position without the benefit of the L-shaped guide. However, this L-shaped guiding opening does not eliminate the wear on the select and connect bars during the opera tion of the crosspoints. A further disadvantage of the Vazquez arrangements is that the contact area is limited. The contact which is being made between the movable spring member and the fixed spring member is in a point to point contact giving limited area.

SUMMARY oF THE INVENTION In the present invention a cross coordinate switch is provided which allows the crosspoints to be made by including on a printed circuit board the fixed and movable contacts, the movable contacts preferably comprising flat spring members. These flat spring members provide a greater area of contact surface and hence a better connection than that provided in the Vazquez or Grundig arrangements cited previously. In the present invention an actuator, having a cam surface for closing the movable contacts onto the fixed contacts, is slidably supported above the printed circuit board on a frame, and the camming of the flat springs against the actuator during operation and release produces only minimal wear.

The actuator in the present invention includes an outwardly extending arm with the finger extending upward from its feee end. A select and connect bar are positioned on the frame above the actuator to cooperate with the finger and with a proper sequence of operation of the select and connect bars in cooperation with the finger, move the actuator from a first to a second position to operate the predetermined crosspoint. Preferably the select and connect bars are made from plastic material, as is the actuator, the arm and finger portions thereof and hence the operation of the crosspoint produces very minimal wear on the select and connect bars.

The cross coordinate matrix of the present invention is mounted on a plug-in printed circuit board which allows fast and simple replacement of the matrix if for some reason there should be a failure at any of the crosspoints. On the printed circuit board is mounted a frame which supports a plurality of solenoids for operating individual ones of an orthogonal array of operat-' ing members. The frame also supports an actuator above each crosspoint on the printed circuit board. A cover is included over the frame and serves to prevent extraneous material from entering the matrix and contaminating the switch crosspoints, and with flexible select and connect bars the cover serves to hold them into place on the upper surface of the frame. The cover also clamps the solenoids firmly into place in the frame.

One of the objects of the present invention is to provide a crosspoint matrix mounted on the printed circuit board which may be easily removed and installed for operation in a telecommunication switching system.

Another object of the present invention is to provide a crosspoint matrix in which operation and release of the crosspoints produces only minimal wear on the switch components.

A further object of the present invention is to provide a self-latching electromechanical crosspoint switch in which a predetermined crosspoint may be actuated and released by applying momentary voltage pulses in the proper sequence to select and/or connect solenoids which operate the select and connect bars of the predetermined crosspoint.

BRIEF DESCRIPTION OF THE DRAWING FIG. is an-exp'loded perspective view of the major building blocks of the crosspoint matrix of the present invention. Part of the printed circuit board and cover portion of the switch have been shown in phantom.

FIG. 2 is a top plan view of one of the crosspoints-of the present invention in which the select and connect bars have been eliminated to better illustrate the position of the actuator in the frame, the actuator being shown in the unoperated position.

FIG. 3 is a sectional view taken along the lines 3-3 of FIG. 2.

FIG. 4 is a sectional view taken along the lines 44 of FIG. 2.

FIG. 5 is a side view of a typical crosspoint when the actuator has been moved forward and the movable contact hasbeen cammed into touch with the fixed contact on the printed circuit board.

FIG. 6 is a top plan view of a typical crosspoint which includes the select and connect bars in their normal position and the actuator and its associated parts in the unoperated position.

'FIG. 7 is a top plan view of a typical crosspoint in which the connect bar has been moved by its associated solenoid.

FIG. 8 is a top plan view of a typical crosspoint in which the select bar for the crosspoint has been actuated.

FIG. 9 is a top plan view of a typical crosspoint showing the return of the connect bar to its original position and the movement of the actuator to a forward position.

FIG. 10 is a top plan view showing the release of the select bar which completes the operational sequence for the crosspoint.

FIG. 11 is a top plan view of an alternative embodiment of an actuator means.

FIG. 12 is a sectional view taken along the lines 12l2 of FIG. 11.

FIG. 13 is an enlarged sectional view taken along the lines 13--13 of FIG. 1.

FIG. 14 is a sectional view taken along lines 14-14 of FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will best be understood by reference to the drawing figures, wherein now referring to FIG. 1 it will be noted that the matrix switch includes a printed wiring board 1 having groups of movable and corresponding fixed contact sets indicated by reference character 2. A portion of printed wiring board 1 is shown in the phantom view and it should be understood that there would be a continuing row and column configuration of movable and fixed contact sets 2, and in this particular embodiment there would be eight rows and eight columns of contact sets 2. The movable and fixed contact sets 2 will be described in detail subsequently, however they are illustrated in FIG. 1 to give the proper perspective of their arrangement on the printed wiring board 1. A second major portion of the matrix switch is the frame 3. An orthogonal array of operating members are supported on frame 3, and as viewed in FIG. 1, those members aligned in the rows are called connect bars and are designated by reference character 7. Connect bars 7 may be individually operated by connect solenoids 6, one solenoid 6 being provided for each connect bar 7. In a similar manner, a plurality of select solenoids 5- as supported on frame 3 and are used to energize the plurality of select bars 4. The matrix switch is arranged such that for each intersection of a select and connect bar there is a corresponding movable and fixed contact set 2. The movable contact portion of the set is closed against its associated fixed contact set by the movement of an actuator, which will be more fully disclosed in later drawing figures, from a first or rest position to its second or operated position by the proper sequence of operation of the select bar 4 and connect bar 7 at the particular crosspoint. It will be noted in FIG. 1 that the fixed contacts 12 of the movable and fixed contact sets 2 are brought out to tabs 9 by circuit paths 10. Printed wiring board 1 is what is termed a double sided board and circuit paths (not shown) on the opposite side of the board, are used to make electrical connections from movable contacts 11 to tabs (not shown) on the other sides of the board. All of the movable contacts 11 are electrically connected in common on a column basis as seen in FIG. 1, and all of the fixed contacts 12 are electrically connected in common on a row basis. Hence it will be appreciated that an electrical connection may be made from any row to any column by appropriately pulsing the row and column solenoids which intersect at the desired crosspoint.

A suitable number of holes 13 are provided in printed wiring board 1 so that self-tapping screws (not shown) may be passed from the underside of printed wiring board 1 through holes 13 to secure frame 3 rigidly to printed wiring board 1. It will also be noted that cover 14 includes holes 15 so that similarly a self-tapping screw 16 may be passed through hole 15 and secure the cover 14 over the top of frame 3. Frame 3 includes a rim [7 which completely encircles the outer perimeter of the upper portion of frame 3, and serves to support cover 14 slightly above the orthogonal array of select bars 4 and connect bars 7. Select bars 4 are slidably supported on floor 18 of frame 3 and connect bars 7 are slidably supported on the array of select bars 4.

In order to better understand the operation of an individual crosspoint, at this point your attention is directed to FIG. 2, which is a top plan view of one of the crosspoints of the matrix switch shown in FIG. 1 with the select and connect bars for that crosspoint removed so that it is easier to see the remaining crosspoint actuation parts. First it will be noted that actuator 19 is slidably supported on the floor 18, acutator 19 having been snapped into slots 20. Actuator 19 may be freely moved forward or back within slots 20. The total support arrangement for actuator 19 is better illustrated in later drawing figures. It will be noted that actuator 19 includes an arm 21 which extends from the actuator and is integral therewith, and further it will be observed that a pin 22 is included on the free end of the arm 21. An opening 23 is included in the floor 18 at the crosspoint so that the arm 21 and pin 22 may freely move forward and back during the actuation of a crosspoint. During the operation of the crosspoint, the free end of arm 21 traverses from the free or unrestricted area, the position in which it is illustrated in FIG. 2, to the restricted area at the upper end of opening 23. Arm 21 is molded as a part of actuator 19 and inherently includes a bias which tends to force the pin 22 to the right as viewed in FIG. 2. The necessity of this bias will become apparent subsequently when the operation of a typical cross-point is explained. A subfloor 24 is included beneath the free end of arm 21 and pin 22. Subfloor 24 is just slightly below the free end of arm 21 and pin 22 and serves to prevent any downward flexing of the arm 21 during the operation or release of the crosspoint.

Now referring to FIG. 3, which is an enlarged sectional view taken along the lines 33 of FIG. 2, there it will be seen that the major portion of actuator 19 rests below the lower surface of floor 18. The two outer edges of actuator 19 extend upward in a pair of wings 25 which include tabs 26 on the free end thereof. With this arrangement, actuator 19 may be inserted from beneath the floor 18 and upon the tabs 26 passing through the upper surface of floor 18 the tabs 26 retain the actuator 19 in the slots 20. It will also be observed in FIG. 3 how the movable contacts 11 extend from printed circuit board 1 upward and touch cam surface 19a of actuator 19. Also in FIG. 3 it will be observed that for each movable contact 11 there is a fixed contact 12 on the printed circuit board 1.

Now referring to FIG. 4, which is a sectional view taken along the lines 44 of FIG. 2, it will be seen that with the actuator 19 in its rearward position, movable contact 11 is extending upward from printed circuit board 1 into contact with cam surface 19a, but the free end of movable contact 11 is not touching its associated fixed contact 12. During the production of the switch, the individual movable contacts 11 will be inserted into printed wiring board 1 so that the end 27 will extend through a plated through hole 28 in printed wiring board 1 and a conventional soldering technique will be employed to affix end 27 via solder means to the plated through hole 28. For clarity the solder has not been shown in FIGS. 4 and 5. As is shown in FIG. 4, movable contact 11 will, under its own spring bias, be normally upward and out of contact with fixed contact 12 when actuator 19 is in its rearward position.

The operated position of a typical crosspoint is illustrated in FIG. 5 where it will be noted that actuator 19 has been moved forward so that the free end of arm 21 has moved into the restricted area of opening 23 and cam surface 19a of actuator 19 has pressed movable contact 11 into engagement with its corresponding fixed contact 12. It will be observed in FIG. 4 that a portion of movable contact 11 extends upward, substantially above the area of contact with cam surface 19a of actuator 19 and then descends toward its associated fixed contact 12. With this configuration when actuator 19 is moved forward, movable contact 11 touches fixed contact 12 before the full stroke of actuator 19 is completed. Further movement of actuator 19 presses contact 11 down with greater force against contact 12 and also imparts a sliding motion between the free end of contact 11 and fixed contact 12. This sliding action is produced by the displacement of that portion of contact spring 11 which initially extends above the area of contact with cam surface 19a of actuator 19. When actuator 19 moves into the area formerly occupied by the upper portion of spring contact 11, the free end of contact 11 is forced to move to the left, as viewed in FIGS. 4 and 5, producing a wiping motion between the fixed and movable contacts which gives a self-cleaning action to the contacts.

Your attention is directed to FIG. 6 which is an enlarged top plan view of a typical crosspoint showing the actuator 19 in its rearward position and select bar 4 and connect bar 7 in their unoperated positions. It will be noted that pin 22 of arm 21 extends upward adjacent to projection 29 of select bar 4. Pin 22 extends further upward and through a somewhat U-shaped opening 30 in connect bar 7. It will be recalled that the arm 21 of the actuator 19 includes a molded-in bias which normally positions pin 22 to the right, and with the select bars 4 in place the pins 22 of each crosspoint tend to hold the select bars 4 in their unoperated positions. With the crosspoint in its unoperated condition as shown in FIG. 6, pin 22 will be in the position as shown in FIG. 6, the connect bars 7 being normally held in this position by a spring (not shown in this FIG. however) individual to each of the connect solenoids 6. Hence,

upon the operation of a connect solenoid 6 for example, the connect bar is pulled downward as viewed in 5 FIG. 7 against the spring individual to the connect bar 7. During the operation of select bar 4, the select solenoid 5 individual to the operated select bar 4 must pull against the bias inherent in each of the arms 21 associated with the energized select bar 4.

It will be recalled from the foregoing that in order to operate a crosspoint actuator 19 must be moved from its rearward position as illustrated in FIGS. 2. 4 and 6 to its forward position as illustrated in FIGS. 5, 9 and 10. The sequence of operation of the select bar 4 and connect bar 7 to operate a crosspoint is illustrated by the first step which is shown in FIG. 7. In FIG. 7 it will be noted that connect bar 7 is first moved as indicated by the arrow, by its associated connect solenoid 6 against the spring force of that solenoid to the position shown in FIG. 7. It will be noted that the pin 22 is now in line with the upper leg of the U-shaped opening 30 and may be moved into the upper leg by select bar 4 and into trapping zone 30a. The next step in the operational sequence is illustrated in FIG. 8 wherein select bar 4 is pulsed by its associated select solenoid 5 and moves pin 22 into trapping zone 30a of the upper leg of U-shaped opening 30. At this point the operating pulse which has been applied to connect solenoid 6 ceasesand connect bar 7 is then returned to the position shown in FIG. 9 by the spring associated with the connect solenoid. In FIG. 9, it will be noted, that upon release of the connect bar 7 the pin 22 which was moved into trapping zone 30a of connect bar 7 has been moved forward which of course translates actuator 19 to its forward position and operates the crosspoint. Now that pin 22 has been moved forward it is no longer necessary for select bar 4 to be retained in its energized position since surface 31 of opening 23 retains pin 22 in trapping zone 30a and hence the pulse to select solenoid 5 is ceased and select bar 4 is returned to its neutral position by the bias of the remaining arms 21 in this column of the crosspoint switch.

FIG. 10 shows the crosspoint in its operated position wherein select bar 4 has been returned to its unoperated position. This completes the operation of a typical crosspoint and it will be appreciated at this point that the crosspoint is closed and will remain closed without maintenance of a holding current since the solenoids are now both in their neutral or unenergized condition.

In order to release a crosspoint which has been operated, it is merely necessary to apply a voltage pulse to the connect solenoid 6 which controls the connect bar that intersects the crosspoint to be released. Upon .reenergizing the connect solenoid 6, connect bar 7 will move in the direction indicated by the arrow. in FIG. 7 and in so doing will move pin 22 and its actuator l9-to the unoperated position. During the return of the actuator 19 to the unoperated position the bias exhibited by arm 21 will cause the free end of arm 21 to travel along surface 31 of upper portion of opening 23 and hence pin 22 will be guided out of trapping zone 30a and returned to the unrestricted area of opening 23 and into the unoperated position as shown in FIGS. 2, 4 and 6. With the actuator 19, arm 21, and pin 22 in this unoperated position, it will be appreciated that any other crosspoint in the row containing connect bar 7 may be actuated since with pin 22 in its normal position by virtue of subsequent reoperation of the connect bar 7, connect bar 7 will not move pin 22 and actuator 19 upon operation thereof since the base of the U-shaped opening 30 allows free and uninhibited movement about those pins 22 which are not moved into the trapping zone 30a of the upper leg of U-shaped opening 30.

An alternative arrangement for operating a crosspoint using a somewhat different arm on the actuator means is illustrated in FIG. 11 which is a top plan view of an alternative embodiment of an actuator means. As viewed in FIG. 11 it will be noted that actuator 32 includes an upstanding stud 33 which is a molded integral part of the actuator 32. Stud 33 includes a slot 34 for receiving one end of a spring 35. With one end of spring 35 inserted into slot 34 the other end extends outward from stud 33 in an arm portion 36, which it will be noted is biased upward as viewed in FIG. 11. The end of spring 35 opposite stud 33 is terminated in a folded, upward extending portion 37. Portion 37 serves the same function in this embodiment as does pin 22 in the previous embodiment. To better appreciate the configuration of this alternative, embodiment your attention is directed to FIG. 12 which is a sectional view taken along the lines 12-12 of FIG. 11. Actuator 32 here again, as was true with actuator 19, includes wings 38 which may be pushed upward through floor 18 and snapped into the slots 20 for the crosspoints. Also as was true with the actuator 19, tabs 39 are included on the free end of the wings 38 to hold the actuator 32 into slidable engagement with floor 18 once the actuator 32 has been snapped into position on floor 18. Actuator 32 includes cam surface 32a which performs the same function as cam surface 19a of actuator 19. In order to hold spring 35 firmly in place once it has been inserted into slot 34 of stud 33, a technique called spin welding may be utilized to melt and flow the plastic material on the upper end of stud 33 downward onto the upper edges of spring 35; this flow of material is indicated in FIG. 11 by reference character 46. This flow could also be accomplished through ultrasonic welding or staking.

In FIG. 13, which is an enlarged sectional view taken along the lines 13-13 in FIG. 1, the relationship between the solenoid 6 and connect bar 7 is illustrated. Connect solenoid 6 is supported in the matrix switch by the combination of frame 3 and cover 14, which when held together as mentioned previously by screws 16, clamps the solenoid 6 into place. Each solenoid 6 includes a plunger 40, which is shown in FIG. 13 in its forward position, which is normally retained in this forward position by helical spring 41. It will be recalled from the foregoing that solenoids do not require separate springs in conjunction with the plunger (not shown) since the plunger associated with each select solenoid 5 is kept in its outward or unoperated position by the bias from arms 21 of actuators 19. However, in all other respects solenoids 5 and their associated plungers are identical to solenoids 6 and plunger 40 in their operation and relationship within the frame 3. The free end of plunger 40 is terminated in a circular section 42 which is of a larger diameter than plunger 40 which is inserted into the solenoid 6. As can be seen in FIG. 13, the upper part of section 42 is fitted into a semicircular opening 43 in connect bar 7. This fit be- .tween section 42 and the semicircular opening 43 allows the solenoid 6 to operate and release connect bar 7. It will be noted that the forward travel of plunger 40 is limited by the lower portion of section 42, which by virtue of spring 41, is forced into engagement with the wall section 44 of frame 3. In order to establish a predetermined stroke for the connect bars, an upward pro- 5 jection 45 from frame 3 has been molded as a part of frame 3. This upper projection 45 determines the stroke of solenoid 6 since the lower portion of section 42 of plunger 40 will strike the projection '45 upon its rearward travel when solenoid 6 has been energized. Wall section 44 stops the forward travel of plunger 40 and hence eliminates the impact of plunger 40 on the select and connect bars.

In a like manner, the stroke of select solenoids 5 are also determined by a similar wall and upward projection (not shown) from frame 3 in the corresponding positions relative to each of the select solenoids 5. Hence it will be appreciated that the maximum stroke of the select and connect bars may be determined by merely molding into frame 3 appropriately dimensioned wall portions.

FIG. 14 is a sectional view taken along the lines 14-14 of FIG. 13, and illustrates plunger 40, section 42 and their relationship with frame 3. Upward projection 45 from frame 3, connect bar 7, section 42 and upper surface 18 of frame 3 are also illustrated.

What is claimed is:

1. A cross coordinate switching arrangement comprising:

a planar printed circuit board having thereon a plurality of fixed and a plurality of movable contacts extending from said board in engageable relationship with said fixed contacts;.

a plurality of actuators slidably supported adjacent to said movable contacts, said actuators including a cam surface engageable with said movable contacts and said actuators being movable in a plane substantially parallel to the plane of said printed circuit board, for selectively camming said movable contacts into engagement with their associated fixed contacts;

and

an orthogonal array of operating members selectively engageable with said actuators and adapted to selectively move said actuator means from a first to a second position to thereby operate the movable contact at the selected cross coordinate.

2. The switching arrangement as claimed in claim 1 including a frame secured to said printed circuit board for slidably supporting said actuators and said operating members.

3. The switching arrangement as claimed in claim 2 wherein each said actuator includes an arm having a finger extending from the free end thereof, and said frame includes apertures through which said fingers extend, each of said fingers being positioned for selective engagement with the operating members of a predetermined coordinate of said operating members whereby a predetermined actuator may be moved from said first to said second position by selective engagement of the operating members with the finger of said predetermined actuator.

4. The switching arrangement as claimed in claim 3 wherein said aperture adjacent the free end of said arm includes a restricted and an unrestricted area.

5. The switching arrangement as claimed in claim 4 wherein each said arm biases its finger toward said unrestricted area.

6. The switch as claimed in claim wherein said frame includes a platform positioned below the free end of said arms.

7. The switching arrangement as claimed in claim 1 wherein said movable contacts are cantilever-mounted springs.

8. A coordinate switch comprising:

a planar printed circuit board having a plurality of fixed contacts thereon, and a plurality of movable contacts extending from said printed circuit board for selective engagement with corresponding fixed contacts;

a frame supported in spaced relationship above said printed circuit board;

a plurality of actuator means slidably supported by said frame for movement in a plane substantially parallel to the plane of said printed circuit board, each said actuator means including a cam surface for pressing an associated movable contact into engagement with its corresponding fixed contact and each said actuator means including an arm having an upturned free end;

a plurality of select bars having projections engageable with said free ends of said actuator arms; and

a plurality of connect bars having U-shaped openings, including a trapping zone, for receiving said free ends of said actuator arms, said select bars being selectively operable to move their associated free ends of said arms into the legs of said U-shaped openings whereby upon movement of one of said free ends into a trapping zone of a connect bar said free end and hence the actuator may be moved by said connect bar, from a first to a second position to thereby operate the contacts associated with said displaced actuator.

9. The coordinate switch as claimed in claim 8 including solenoid means supported by said frame said solenoid means being operably coupled to and individual to each said select and connect bar for selectively moving said select and connect bars.

10. The coordinate switch as claimed in claim 9 wherein each said solenoid means includes a plunger and said frame includes a stopping surface for limiting the stroke of said plungers.

11. The coordinate switch as claimed in claim 8 wherein said movable contact includes a curved portion which extends above the contact area between said actuator and said movable contact whereby upon movement of said actuator from said first to said second position said actuator displaces said curved portion and hence moves said free end of said movable contact downward and outward to produce a sliding movement between said fixed contact and said free end of said UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No- 3863044 Dated January 28, 1975 I MAURICE D. MC CORMICK It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 9, line 6, before 'Springs" add leaf Signed and sealed this 1st day of April 1975.

s 11;) Attest:

C. I'U-IRSI-XALL DAMN Commissioner of Patents and Trademarks RUTH C. I'LKSON :Xttesting Officer FORM PO-IOSO (10-59) USCOMM-DC OOB'IO-PBD 0.5. GOVIIIIIINT PRINTING OFFICE 2 "Cl 0-Sli-ll4.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3863044 Dated January 28, 1975 In nt D. MC

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 9, line 6, before "springs" add leaf Signed and sealed this 1st day of April 1975.

Attest:

C. I-IARSHALL D.-KNN Commissioner of Patents and Trademarks RUTH C. I-LKSON Attesting Officer F ORM PC4050 (10-69) USCOMM-DC 603164 69 u.s. covllmlinr rmu'rme OFFICE nu o-ale-au.

Claims

1. A cross coordinate switching arrangement comprising: a planar printed circuit board having thereon a plurality of fixed and a plurality of movable contacts extending from said board in engageable relationship with said fixed contacts; a plurality of actuators slidably supported adjacent to said movable contacts, said actuators including a cam surface engageable with said movable contacts and said actuators being movable in a plane substantially parallel to the plane of said printed circuit board, for selectively camming said movable contacts into engagement with their associated fixed contacts; and an orthogonal array of operating members selectively engageable with said actuators and adapted to selectively move said actuator means from a first to a second position to thereby operate the movable contact at the selected cross coordinate.

6. The switch as claimed in claim 5 wherein said frame includes a platform positioned below the free end of said arms.

8. A coordinate switch comprising: a planar printed circuit board having a plurality of fixed contacts thereon, and a plurality of movable contacts extending from said printed circuit board for selective engagement with corresponding fixed contacts; a frame supported in spaced relationship above said printed circuit board; a plurality of actuator means slidably supported by said frame for movement in a plane substantially parallel to the plane of said printed circuit board, each said actuator means including a cam surface for pressing an associated movable contact into engagement with its corresponding fixed contact and each said actuator means including an arm having an upturned free end; a plurality of select bars having projections engageable with said free ends of said actuator arms; and a plurality of connect bars having U-shaped openings, including a trapping zone, for receiving said free ends of said actuator arms, said select bars being selectively operable to move their associated free ends of said arms into the legs of said U-shaped openings whereby upon movement of one of said free ends into a trapping zone of a connect bar said free end and hence the actuator may be moved by said connect bar, from a first to a second position to thereby operate the contacts associated with said displaced actuator.

9. The coordinate switch as claimed in claim 8 including solenoid means supported by said frame, said solenoid means being operably coupled to and individual to each said select and connect bar for selectively moving said select and connect bars.

11. The coordinate switch as claimed in claim 8 wherein said movable contact includes a curved portion which extends above the contact area between said actuator and said movable contact whereby upon movement of said actuator from said first to said second position said actuator displaces said curved portion and hence moves said free end of said movable contact downward and outward to produce a sliding movement between said fixed contact and said free end of said movable contact.