CA1331479C - Line protector for a communications circuit - Google Patents
Line protector for a communications circuitInfo
- Publication number
- CA1331479C CA1331479C CA000609187A CA609187A CA1331479C CA 1331479 C CA1331479 C CA 1331479C CA 000609187 A CA000609187 A CA 000609187A CA 609187 A CA609187 A CA 609187A CA 1331479 C CA1331479 C CA 1331479C
- Authority
- CA
- Canada
- Prior art keywords
- conductive
- devices
- line
- line protector
- protector
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T4/00—Overvoltage arresters using spark gaps
- H01T4/06—Mounting arrangements for a plurality of overvoltage arresters
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
ABSTRACT
A line protector for a communications circuit.
The line protector has an overvoltage arrestor such as a three electrode gas tube, two of whose electrodes are connected to the line input terminals of the protector by associated conductive elements projecting from the protector base. The third electrode is connected to the ground terminal. The line protector also has two positive temperature coefficient resistors (PTCRs) which protect against marginal overcurrents. Conductive elements connected to the line protector's equipment terminals also project from the base in the same direction as the line input terminal conductive elements project. Each PTCR is in contact with an associated one of the two line input terminal conductive elements and an associated one of the two equipment terminal conductive elements.
A line protector for a communications circuit.
The line protector has an overvoltage arrestor such as a three electrode gas tube, two of whose electrodes are connected to the line input terminals of the protector by associated conductive elements projecting from the protector base. The third electrode is connected to the ground terminal. The line protector also has two positive temperature coefficient resistors (PTCRs) which protect against marginal overcurrents. Conductive elements connected to the line protector's equipment terminals also project from the base in the same direction as the line input terminal conductive elements project. Each PTCR is in contact with an associated one of the two line input terminal conductive elements and an associated one of the two equipment terminal conductive elements.
Description
~ "~ ~65 LINE PRO~E~TOR FOB ~ COMMu~Ic~TION$ ~I~Ç~IT
Background o~ the Invention 1 Field of ~h~ In~entiQn The pr~sent invention relates to protec~or modules which are u~ed in various locations such as telephone central office~ to protec~ the inside equipment from damage as a rQ3Ult of overvoltage and overcurrent conditions ~hat may occur on the out~ide lines and more particularly to such a module which uses positive temperature cos~iaient resistors (PTCRs) ~o pxovide overcurrent pro~ea~ion. . :
Background o~ the Invention 1 Field of ~h~ In~entiQn The pr~sent invention relates to protec~or modules which are u~ed in various locations such as telephone central office~ to protec~ the inside equipment from damage as a rQ3Ult of overvoltage and overcurrent conditions ~hat may occur on the out~ide lines and more particularly to such a module which uses positive temperature cos~iaient resistors (PTCRs) ~o pxovide overcurrent pro~ea~ion. . :
2. ~criptlon o~ the Prlox_~t .
There are many well known modules which are used at ~elephone company central offices and increas$ngly at othsr locations to provide protection against any overvolta~e and overcurrent condikions that may ocour on the telephone line pair. One exa~ple o~ such a ;:
module is that shown in U.S. Patent No. 3,~75,664 :
~hereinafter the '664 patent) which is assigned to the same assignee as is ~he present invention.
The module de~cribed in the '664 patent US2S a three element cold cathode gas ~ube ~o provide protection a~ains~ an overvoltag~ condition on the telephone line pair to which the module is conneat~d.
Protection against a sustained overcurrent condition ~an Qveraurrent a~soci~ted with an overvoltaqe of su*~icient ampli~ude to cause the gas tube to conduct) on the line pair is provided by having slugs o~ low malting poin~ solder in contact with the Qnd terminals of th~ ~as tube. The occurrence o~ a sustained overc~rren~ condition on either line of the lins pair protec~ed by the module aauses the associated slug ~o melt. ~rhe meltlng of the slug allows the associated ' ''~.~'"
~~~ 8~50 :L 3 3 ~
end terminal of the gas tube to coma in contact with the qround terminal of the module, there by per~anently grounding the ass~ciated line. A more detailed description o~ how the module shown in the '664 patent pr~vides overvoltage and sustained overcurrent protection may be obtained by referring to that patent.
The module described in the '664 patent does not provide pro~ection agains;t a marginal overcurrent condition, i.a., an overcurrent condition associated with an overvoltage which is not of sufficient amplitude to cause the gas tube to c~nduct~ In other words, a marginal overcurrent does not ~low throu~h th~ gas tube. Therefore, the module of the '664 patent should no~ be used with ~hose line pairs where BUCh a condition may occur.
As di6cu~s~d in the '664 pa~ent, the module disclosed therein has certain advantages. ~mong them are the elimination of a spring to carry large overcurrents of long duration, relatively short current paths, standard 5 pin base, ease of assembly and its relatively small and compact configuration.
It is de~irable that such a module also be capable o~
prote¢ting against marginal overcurrents.
Pro~ction agains~ such over~urrents has typically been provided by using an in-line heat coil which heats a ~usible solder element. The solder element ~elts during the occurrence of such a condition. One example o~ a protector module which us~s heat coil~ is disclosed in U.S. Patent No. 3,849,750 (hereinafter the '750 patent) also assigned to the same assignee as is the present invention. As shown in the '750 patent, the heat coil and overvoltage protection dQViCe, e.g., two element gas tube, are in-line and coaxial. In addition, a spring is used to bring a ~33~ ~ ~9 pair of contacts together to ~orm the direct metallic path from th~ line to ground when the heat coil fuæible element melts, W~ile it is desirable to provide protection against marginal overcurrents in a module o~ the typ~
shown in the '664 patent, it is not feasible to u~e a he~t coil therein ~or such protection. A comparison of the structure o~ the modules of the '664 and '750 patents makes that clear. In addition, a heat coil is undesirable in that when it do~s operate to provide protection against marginial overcurrenks, the fusible solder melt~ and the line is permanently grounded. It is then necessary to r~place the module. Until that is done, the telephone line is out o~ service.
It was khen decided to provide such protection in a module of the type sho~n in tne '664 patent ~y using a solid state device, such as a PTCR, whose resistance substantially increases when current ~low through the de~ice causes th~ d~vice temperature to reach a predeter~ined temperature above ambient. Such a devi~e perf~rms the ~ame function as a heat coil in that current is limitad but without the undesirable permanent groundinq of the line described above. ~he flcw o~ an overcurrent through the device aauses its temperature to reach that temperature at wnich the r~sistance o~ the device abruptly increases by ~everal order~ o~ magnitude to tnereby limit the current.
When tha overcurr~nt condition ceases, the deviçe cools and its reslstance decreases to its a~bient te~perature valua. The device is then ready for the nsxt occurrence Q~ an overcurre~t conditlon.
~u~mary ~ the Inv~n~io,n A line protecto~ for a communications cirauit.
The lina protector has an insulating base. It als~
has a surge ~oltags arrestor which has opposed electrodes.
::,'' .~
~ 3 3 ~ 9 8~50 The line protector further includes first and second conductive element~ in ~he base. The elements each project in one direction ~ro~ ~he ~ase and are in eleatrical contact, respec:tive~y, with the opposed electrodes. I~ also i.ncludes third and fourth conductive elements in the base. ~h~ third and fourth elements also project from the base in the same dir~ction that the firs~ and second elements projec~
and are in spaced relationship with ths first and ~econd element~.
The line protector furth~r includes two device6, one o~ which is in con~act with the ~irst and third elem~ntsi to provi~e a conductive path beitween those elements and the other of which is in contaat with the second and fourth elements to provide a conductive betwQen tho~e elements. Each Qf the devices has the capa~ y to limit the amplitude of the current ~lowing through it to be no greater than a predetermined amplitude.
e~cription ~f t~Q ~rawings ~ ig. 1 i~ a simplified ~chematic diagram illustrating a telephone line pair with a protector device connecting each line to ground in an ::
overvoltage and/~r overcurrent condition;
Fig. 2 is an exterior perspective Yiaw o~ the protector housing and base o~ this invention wherein the prot~ctor unit is contained;
Fig. 3 is a sectional Vi8W on an enlarged scale taken along line 3-3 o~ Fig. 2 ~howing the protector structure and mounting terminal clip6 associated therewith: -Fig. 4 is an exploded perspectiYe view of the protec~Gx unit structure of this invention, and ` 133~.~7~ 8650 Figs. 5a and 5b are front and side views, respectively, of the base assembly of the protector module of the present invention.
Description of the Preferred Embodiment Referring now to Fig. 1, there is shown a simplified circuit of a telephone line pair, i.e., tip (T) and ring (R), with the protector module of the present invention illustrated somewhat diagrammatically and connected therebetween. As Fig. 1 is, except as otherwise described below, identical to Fig. 1 of the '664 patent, the same reference numerals are used to identify the same elements.
It is not necessary then to describe how three element gas tube protector element 20 provides a connection to ground for a sustained overvoltage appearing either on tip line 11 at terminal 13 or ring line 12 at terminal 14. The ~664 patent provides such an explanation and `in any case the operation of the three element gas tube protector element in the circuit shown in Fig. 1 is now very well known to those skilled in the art.
The difference between Fig. 1 of the present invention and Fig. 1 of the '664 patent is the connection of each of the junction of tip line 11 and conductor 24 to terminal 16, and of ring line 12 and conductor 26 to terminal 17 by a resistor R which has a positive temperature coefficient, i.e., R is a PTCR. The flow of current in either line 11 or line 12 causes the associated PTCR to dissipate power. As a result, the temperature of the PTCR rises. When the temperature has risen to the point at which the resistance of the PTCR abruptly increases by several orders of magnitude, the amplitude of the current is limited to a safe level. In this manner, the equipment, be it a switch or telephone, connected to .: '." ~ ' ~,;~,.
,' '~ ':`--` ~ 33~ ~9 terminal6 16 and 17 is protected from excessive current.
Of course, it should be appreciated that if the flow of current through either PTCR is due to an overvoltage condition which is su~ficient ~o cause the associated portion o~ gas ~ube 20 to connect the line on which the condition has occurred to ground, then ~he current will flow to ground. If the overcurrent is sustained, then the associated solder slug will melt permanen~ly connecting the line to ground.
Referring now to Fig. 2, there is shown an ex~erior perspective view of the housing 30 for the protector module of the present invention. As Fig. 2 is identical in all respects to ~ig. 2 of the '664 patant, the sam~ reference numerals used therein are used herein. Extending from tha base 38 (see Fig. 3~
of housing 30 are the equipment pins 39 and 43, the line pins 40 and 44, and the ground pin 48. As is well known in the art, the equipment pins are electrically connected to the T and R line~ of the line pair for the equipment to be protected while the line pins are electrically connected to the T and R
lines of the incoming line pair.
Referring now to Fig. 3, there is shown on an enlarged scale a sectional view o~ the protector module of the present invantion. As Fig. 3 is, except as other~ise described below, identical to ~ig. 3 of ~he '664 patent, th~ same re~arence numerals are used to identify the same elements. As with the module of the '664 patent, the module of the present invention includes first and second leaf spring connector elements 42 and 47 which makes contact with end caps 57 and 56, respectively of the gas tube 20. In addition, the module o~ the present invention also includes, as does the modula of tha '664 patent, a ~ ~ 3 ~
~lip member 50 at one end o~ ground pin 48~ ~ember 50 has window or cut-out 51 for firmly ~ngaging the center or ground terminal 27 o~ protector 20. The module of the present invsntion further i~cludes, as doe~i the module o~ th~ '664 patent, stop sleeve ~3 which is positioned over t~le bent portlon 74 (see Fig~
4) of ground pin 48.
In the module o~ the '664 pa~ent, tha bent portion 41 o~ s~ring connector element 42 contacts pins 39 and and ~he bent por~ion 46 of spring connector element 47 contacts pins 43 and 44. In ~he module of the present invention, t~e ben~ por~ion 41 o~ element 42 çont~icts only pin 40 and this bent portion 46 of element 47 contacts only pin 44. The contacts with pins 3g and 43 are made by leafspring connector element~ 81 and 82, respectively. Ele~ent 81 is staked to pin 39 and element 82 iS staked to pin 43.
~or~ specifically, i~ is bent portion 84 of element 81 Which ia st~ked to pin 3g and bent portion 85 of element 82 which is staked to pin 43.
Elements 81 and 8~ are each in electrical connection with elements 42 and 47, respeotively through a PTCR assemb}y 83. In ef~ect, the elements 4~ and 81 cooperate t~ hold in place one P~CR asse~ly 83 and elements 47 and 82 cooperate to hold in place another PTCR as~i~mbly ~i3. A comparison of Fig. 3 ~i~h the ~ircuit of Fig. 1 shows tha~ elements 42 and 81 oooperate with one PTCR assembly 83 to provide the p~th fo~ cuxrent ~low from equipment pin 39 to line pin 40 and elements 47 and 82 cooperate with the other PTCR ~issembly 83 to provide the path ~or curren~ flow ~rom equipmen~ pin 43 to line pin 44.
Re~erring now to Fig. 4, there is shown an exploded perspective view o~ the prot~sctor module o~
the pres~nt in~ention. For ease of illustration and :,'~','.'' .` ' ;,:, " ` ~33~ ~7~
because it is identical to the housing 30 shown in the '6~4 patent, the housing is not shown in ~ig. 4. In addition, threQ element gas tube protector element 20 ls not ~ihown in explode~ Porm in Fig. 4. It iB
identical to the protector element 20 of th~ '6~4 patent which is shown in exploded form in Fig. 7 of that paten~ is not necessary to describe ~ig. 4 in any detail as th~ fulnction of the ele~ents shown therein should be evident ~rom the discussion above and in particular ~ne discussion o~ Fig. 3.
PTCR a~sQmbly 83 in~ludas a disc PTCR 83a available from a numb~r of manu~acturers. In one embodim~nt for the protector module o~ the present invention, a leadless disc PTCR available ~rom Cera-mite of Gra~ton, Wiscon~in was used. An insulator 83b in the ~orm of a ring has been placed on the outer ed~e o~ the disc 83a, The purpose of the insulator i3 to snsure that the PTCR makes electrical contact only with the associated connector el~ments 81, ~2 and 82, 47. ~he lower portion of each of connector eleme~ts 42, 47 include three outwardly projecting protuberances 90 which make the electrical contact between the element and one side of the associated one o~ the PTCRs 83a.
That part o~ conneator elements Bl and 82 which ~akes contact with the associated one o~ the two PTCRs 83a are the upwardly project~ng portions 86 and ~7, re~pectively. Portions 86 and 87 each have two contacting fingers 86a and 86b for portion 86 and 87a and 87b ~or portion 87. Each of contacting ~in~ers 86a, 86b, 87a and 87b have an outwardly pro~ecting protub~rance 92 whi¢h as can be seen from Fig. 3 are each in contact with the associated one of the PTCRs ~3a. The fingers then provide two points o~
electrica:L conta¢t between elements 81, 82 and the `` 8650 ~333~
:
_ 9 _ associated one o~ PTCRs 83a. While portions ~6 and 87 could each have ~een delsigned not to have fingers, i.e., a solid piece, th~e u~e of two fingers in each portion i5 desirable because they have in total lower contact resistance than a solid pieee.
In compar~ng ~he module of the present invention wikh that shown in the '66~ patent, it is apparent ~hat t~e conneator element~ ~2 and ~7 of the present invention do not have the shape as is shown therePor in the '664 pa~ent. The reason for that difPerence in ~h~pe is that the protector module o~ the present invention al80 includes connected to its base, connector elements 81 and ~2 which are electrically connected to elements 42 and 47 only through the associated one of the two PTCRs 83a. T~ ensure that ther~ is no other electrical conneGtion betw~en elements ~2 and 81 and element~ ~7 and 82, it was neces~ary to modify the shape oP elements 42 and 47 from tha~ shown in the '664 patent.
In order to complete the understanding o~ the present invention, there is shown in Figs. 5a and 5b front and side vi~ws, respectively, o~ base 30 of the module in assembled relationship with pins 39, 40, 43, and 4~ and connector elements 42, 47, 81 and 82.
Figs. 5a and 5b taken together illustrate the base a~ambly 31 of the module. In Pabricating the module, the base asse~ly may be separately manufactured.
Finai assembly o~ the module then involves inserting one PTCR assembly 83 between elements 42 and 81, another assembly 83 be~ween elements 47 and 82, the bringin~ oP protector element 20 into firm engagement with clip member 50 of ground pin 481 the placement of stop sleev~ 73 on pin 48 and the insertion of pin 48 50 ~ssembled into the hole in base 38 there~or.
Housing :30 is th~n placed over the base assembly 30 . ': ., .,: ;,:
f~ 8650 r~1 that apsrtures 33 and 34 ~see Fig. 2) engage pxotuberances 36 and 37, respectively, in base assembly 31 (see Fig. 5a).
While the present invention has been described in connection with a module that uses a ~hree element, i.e., electrode, gas tube as a surge voltage arrestor it should be appreciated tlhat the arr~stor need not be a gas tube. It should further be appreciated that ~e PTCRs ~unction to limit the amplitude of the current flowing through them to be no greater than a predeter~ined a~plitude.
It is to be understood that the description of the pr~ferred e~bodimant is intended to be only illustrative, rather than exh~ustive, of the present invention. ~ho3e of ordinary skill will be able to ~ake certain additions, del~tions, and/or modifica~ions to ~he embodiment of the disclose~
subject matter without departing rom the spirit o the invention or its scope, as defined by the appended claims~
,.
There are many well known modules which are used at ~elephone company central offices and increas$ngly at othsr locations to provide protection against any overvolta~e and overcurrent condikions that may ocour on the telephone line pair. One exa~ple o~ such a ;:
module is that shown in U.S. Patent No. 3,~75,664 :
~hereinafter the '664 patent) which is assigned to the same assignee as is ~he present invention.
The module de~cribed in the '664 patent US2S a three element cold cathode gas ~ube ~o provide protection a~ains~ an overvoltag~ condition on the telephone line pair to which the module is conneat~d.
Protection against a sustained overcurrent condition ~an Qveraurrent a~soci~ted with an overvoltaqe of su*~icient ampli~ude to cause the gas tube to conduct) on the line pair is provided by having slugs o~ low malting poin~ solder in contact with the Qnd terminals of th~ ~as tube. The occurrence o~ a sustained overc~rren~ condition on either line of the lins pair protec~ed by the module aauses the associated slug ~o melt. ~rhe meltlng of the slug allows the associated ' ''~.~'"
~~~ 8~50 :L 3 3 ~
end terminal of the gas tube to coma in contact with the qround terminal of the module, there by per~anently grounding the ass~ciated line. A more detailed description o~ how the module shown in the '664 patent pr~vides overvoltage and sustained overcurrent protection may be obtained by referring to that patent.
The module described in the '664 patent does not provide pro~ection agains;t a marginal overcurrent condition, i.a., an overcurrent condition associated with an overvoltage which is not of sufficient amplitude to cause the gas tube to c~nduct~ In other words, a marginal overcurrent does not ~low throu~h th~ gas tube. Therefore, the module of the '664 patent should no~ be used with ~hose line pairs where BUCh a condition may occur.
As di6cu~s~d in the '664 pa~ent, the module disclosed therein has certain advantages. ~mong them are the elimination of a spring to carry large overcurrents of long duration, relatively short current paths, standard 5 pin base, ease of assembly and its relatively small and compact configuration.
It is de~irable that such a module also be capable o~
prote¢ting against marginal overcurrents.
Pro~ction agains~ such over~urrents has typically been provided by using an in-line heat coil which heats a ~usible solder element. The solder element ~elts during the occurrence of such a condition. One example o~ a protector module which us~s heat coil~ is disclosed in U.S. Patent No. 3,849,750 (hereinafter the '750 patent) also assigned to the same assignee as is the present invention. As shown in the '750 patent, the heat coil and overvoltage protection dQViCe, e.g., two element gas tube, are in-line and coaxial. In addition, a spring is used to bring a ~33~ ~ ~9 pair of contacts together to ~orm the direct metallic path from th~ line to ground when the heat coil fuæible element melts, W~ile it is desirable to provide protection against marginal overcurrents in a module o~ the typ~
shown in the '664 patent, it is not feasible to u~e a he~t coil therein ~or such protection. A comparison of the structure o~ the modules of the '664 and '750 patents makes that clear. In addition, a heat coil is undesirable in that when it do~s operate to provide protection against marginial overcurrenks, the fusible solder melt~ and the line is permanently grounded. It is then necessary to r~place the module. Until that is done, the telephone line is out o~ service.
It was khen decided to provide such protection in a module of the type sho~n in tne '664 patent ~y using a solid state device, such as a PTCR, whose resistance substantially increases when current ~low through the de~ice causes th~ d~vice temperature to reach a predeter~ined temperature above ambient. Such a devi~e perf~rms the ~ame function as a heat coil in that current is limitad but without the undesirable permanent groundinq of the line described above. ~he flcw o~ an overcurrent through the device aauses its temperature to reach that temperature at wnich the r~sistance o~ the device abruptly increases by ~everal order~ o~ magnitude to tnereby limit the current.
When tha overcurr~nt condition ceases, the deviçe cools and its reslstance decreases to its a~bient te~perature valua. The device is then ready for the nsxt occurrence Q~ an overcurre~t conditlon.
~u~mary ~ the Inv~n~io,n A line protecto~ for a communications cirauit.
The lina protector has an insulating base. It als~
has a surge ~oltags arrestor which has opposed electrodes.
::,'' .~
~ 3 3 ~ 9 8~50 The line protector further includes first and second conductive element~ in ~he base. The elements each project in one direction ~ro~ ~he ~ase and are in eleatrical contact, respec:tive~y, with the opposed electrodes. I~ also i.ncludes third and fourth conductive elements in the base. ~h~ third and fourth elements also project from the base in the same dir~ction that the firs~ and second elements projec~
and are in spaced relationship with ths first and ~econd element~.
The line protector furth~r includes two device6, one o~ which is in con~act with the ~irst and third elem~ntsi to provi~e a conductive path beitween those elements and the other of which is in contaat with the second and fourth elements to provide a conductive betwQen tho~e elements. Each Qf the devices has the capa~ y to limit the amplitude of the current ~lowing through it to be no greater than a predetermined amplitude.
e~cription ~f t~Q ~rawings ~ ig. 1 i~ a simplified ~chematic diagram illustrating a telephone line pair with a protector device connecting each line to ground in an ::
overvoltage and/~r overcurrent condition;
Fig. 2 is an exterior perspective Yiaw o~ the protector housing and base o~ this invention wherein the prot~ctor unit is contained;
Fig. 3 is a sectional Vi8W on an enlarged scale taken along line 3-3 o~ Fig. 2 ~howing the protector structure and mounting terminal clip6 associated therewith: -Fig. 4 is an exploded perspectiYe view of the protec~Gx unit structure of this invention, and ` 133~.~7~ 8650 Figs. 5a and 5b are front and side views, respectively, of the base assembly of the protector module of the present invention.
Description of the Preferred Embodiment Referring now to Fig. 1, there is shown a simplified circuit of a telephone line pair, i.e., tip (T) and ring (R), with the protector module of the present invention illustrated somewhat diagrammatically and connected therebetween. As Fig. 1 is, except as otherwise described below, identical to Fig. 1 of the '664 patent, the same reference numerals are used to identify the same elements.
It is not necessary then to describe how three element gas tube protector element 20 provides a connection to ground for a sustained overvoltage appearing either on tip line 11 at terminal 13 or ring line 12 at terminal 14. The ~664 patent provides such an explanation and `in any case the operation of the three element gas tube protector element in the circuit shown in Fig. 1 is now very well known to those skilled in the art.
The difference between Fig. 1 of the present invention and Fig. 1 of the '664 patent is the connection of each of the junction of tip line 11 and conductor 24 to terminal 16, and of ring line 12 and conductor 26 to terminal 17 by a resistor R which has a positive temperature coefficient, i.e., R is a PTCR. The flow of current in either line 11 or line 12 causes the associated PTCR to dissipate power. As a result, the temperature of the PTCR rises. When the temperature has risen to the point at which the resistance of the PTCR abruptly increases by several orders of magnitude, the amplitude of the current is limited to a safe level. In this manner, the equipment, be it a switch or telephone, connected to .: '." ~ ' ~,;~,.
,' '~ ':`--` ~ 33~ ~9 terminal6 16 and 17 is protected from excessive current.
Of course, it should be appreciated that if the flow of current through either PTCR is due to an overvoltage condition which is su~ficient ~o cause the associated portion o~ gas ~ube 20 to connect the line on which the condition has occurred to ground, then ~he current will flow to ground. If the overcurrent is sustained, then the associated solder slug will melt permanen~ly connecting the line to ground.
Referring now to Fig. 2, there is shown an ex~erior perspective view of the housing 30 for the protector module of the present invention. As Fig. 2 is identical in all respects to ~ig. 2 of the '664 patant, the sam~ reference numerals used therein are used herein. Extending from tha base 38 (see Fig. 3~
of housing 30 are the equipment pins 39 and 43, the line pins 40 and 44, and the ground pin 48. As is well known in the art, the equipment pins are electrically connected to the T and R line~ of the line pair for the equipment to be protected while the line pins are electrically connected to the T and R
lines of the incoming line pair.
Referring now to Fig. 3, there is shown on an enlarged scale a sectional view o~ the protector module of the present invantion. As Fig. 3 is, except as other~ise described below, identical to ~ig. 3 of ~he '664 patent, th~ same re~arence numerals are used to identify the same elements. As with the module of the '664 patent, the module of the present invention includes first and second leaf spring connector elements 42 and 47 which makes contact with end caps 57 and 56, respectively of the gas tube 20. In addition, the module o~ the present invention also includes, as does the modula of tha '664 patent, a ~ ~ 3 ~
~lip member 50 at one end o~ ground pin 48~ ~ember 50 has window or cut-out 51 for firmly ~ngaging the center or ground terminal 27 o~ protector 20. The module of the present invsntion further i~cludes, as doe~i the module o~ th~ '664 patent, stop sleeve ~3 which is positioned over t~le bent portlon 74 (see Fig~
4) of ground pin 48.
In the module o~ the '664 pa~ent, tha bent portion 41 o~ s~ring connector element 42 contacts pins 39 and and ~he bent por~ion 46 of spring connector element 47 contacts pins 43 and 44. In ~he module of the present invention, t~e ben~ por~ion 41 o~ element 42 çont~icts only pin 40 and this bent portion 46 of element 47 contacts only pin 44. The contacts with pins 3g and 43 are made by leafspring connector element~ 81 and 82, respectively. Ele~ent 81 is staked to pin 39 and element 82 iS staked to pin 43.
~or~ specifically, i~ is bent portion 84 of element 81 Which ia st~ked to pin 3g and bent portion 85 of element 82 which is staked to pin 43.
Elements 81 and 8~ are each in electrical connection with elements 42 and 47, respeotively through a PTCR assemb}y 83. In ef~ect, the elements 4~ and 81 cooperate t~ hold in place one P~CR asse~ly 83 and elements 47 and 82 cooperate to hold in place another PTCR as~i~mbly ~i3. A comparison of Fig. 3 ~i~h the ~ircuit of Fig. 1 shows tha~ elements 42 and 81 oooperate with one PTCR assembly 83 to provide the p~th fo~ cuxrent ~low from equipment pin 39 to line pin 40 and elements 47 and 82 cooperate with the other PTCR ~issembly 83 to provide the path ~or curren~ flow ~rom equipmen~ pin 43 to line pin 44.
Re~erring now to Fig. 4, there is shown an exploded perspective view o~ the prot~sctor module o~
the pres~nt in~ention. For ease of illustration and :,'~','.'' .` ' ;,:, " ` ~33~ ~7~
because it is identical to the housing 30 shown in the '6~4 patent, the housing is not shown in ~ig. 4. In addition, threQ element gas tube protector element 20 ls not ~ihown in explode~ Porm in Fig. 4. It iB
identical to the protector element 20 of th~ '6~4 patent which is shown in exploded form in Fig. 7 of that paten~ is not necessary to describe ~ig. 4 in any detail as th~ fulnction of the ele~ents shown therein should be evident ~rom the discussion above and in particular ~ne discussion o~ Fig. 3.
PTCR a~sQmbly 83 in~ludas a disc PTCR 83a available from a numb~r of manu~acturers. In one embodim~nt for the protector module o~ the present invention, a leadless disc PTCR available ~rom Cera-mite of Gra~ton, Wiscon~in was used. An insulator 83b in the ~orm of a ring has been placed on the outer ed~e o~ the disc 83a, The purpose of the insulator i3 to snsure that the PTCR makes electrical contact only with the associated connector el~ments 81, ~2 and 82, 47. ~he lower portion of each of connector eleme~ts 42, 47 include three outwardly projecting protuberances 90 which make the electrical contact between the element and one side of the associated one o~ the PTCRs 83a.
That part o~ conneator elements Bl and 82 which ~akes contact with the associated one o~ the two PTCRs 83a are the upwardly project~ng portions 86 and ~7, re~pectively. Portions 86 and 87 each have two contacting fingers 86a and 86b for portion 86 and 87a and 87b ~or portion 87. Each of contacting ~in~ers 86a, 86b, 87a and 87b have an outwardly pro~ecting protub~rance 92 whi¢h as can be seen from Fig. 3 are each in contact with the associated one of the PTCRs ~3a. The fingers then provide two points o~
electrica:L conta¢t between elements 81, 82 and the `` 8650 ~333~
:
_ 9 _ associated one o~ PTCRs 83a. While portions ~6 and 87 could each have ~een delsigned not to have fingers, i.e., a solid piece, th~e u~e of two fingers in each portion i5 desirable because they have in total lower contact resistance than a solid pieee.
In compar~ng ~he module of the present invention wikh that shown in the '66~ patent, it is apparent ~hat t~e conneator element~ ~2 and ~7 of the present invention do not have the shape as is shown therePor in the '664 pa~ent. The reason for that difPerence in ~h~pe is that the protector module o~ the present invention al80 includes connected to its base, connector elements 81 and ~2 which are electrically connected to elements 42 and 47 only through the associated one of the two PTCRs 83a. T~ ensure that ther~ is no other electrical conneGtion betw~en elements ~2 and 81 and element~ ~7 and 82, it was neces~ary to modify the shape oP elements 42 and 47 from tha~ shown in the '664 patent.
In order to complete the understanding o~ the present invention, there is shown in Figs. 5a and 5b front and side vi~ws, respectively, o~ base 30 of the module in assembled relationship with pins 39, 40, 43, and 4~ and connector elements 42, 47, 81 and 82.
Figs. 5a and 5b taken together illustrate the base a~ambly 31 of the module. In Pabricating the module, the base asse~ly may be separately manufactured.
Finai assembly o~ the module then involves inserting one PTCR assembly 83 between elements 42 and 81, another assembly 83 be~ween elements 47 and 82, the bringin~ oP protector element 20 into firm engagement with clip member 50 of ground pin 481 the placement of stop sleev~ 73 on pin 48 and the insertion of pin 48 50 ~ssembled into the hole in base 38 there~or.
Housing :30 is th~n placed over the base assembly 30 . ': ., .,: ;,:
f~ 8650 r~1 that apsrtures 33 and 34 ~see Fig. 2) engage pxotuberances 36 and 37, respectively, in base assembly 31 (see Fig. 5a).
While the present invention has been described in connection with a module that uses a ~hree element, i.e., electrode, gas tube as a surge voltage arrestor it should be appreciated tlhat the arr~stor need not be a gas tube. It should further be appreciated that ~e PTCRs ~unction to limit the amplitude of the current flowing through them to be no greater than a predeter~ined a~plitude.
It is to be understood that the description of the pr~ferred e~bodimant is intended to be only illustrative, rather than exh~ustive, of the present invention. ~ho3e of ordinary skill will be able to ~ake certain additions, del~tions, and/or modifica~ions to ~he embodiment of the disclose~
subject matter without departing rom the spirit o the invention or its scope, as defined by the appended claims~
,.
Claims (10)
1. A line protector for a communications circuit comprising:
a) an insulating means;
b) a surge voltage arrestor in spaced relationship to said insulating means, said arrestor having opposed electrodes;
c) first and second conductive elements on said insulating means and extending therefrom so as to be in electrical contact, respectively, with said opposed electrodes;
d) third and fourth conductive elements on said insulating means and extending therefrom towards said arrestor; and e) two devices each having the capability of limiting current flowing therein to have an amplitude which is no greater than a predetermined amplitude, one of said devices in contact with said first and third conductive elements to provide a conductive path therebetween and the other of said devices in contact with said second and fourth conductive elements to provide a conductive path therebetween.
a) an insulating means;
b) a surge voltage arrestor in spaced relationship to said insulating means, said arrestor having opposed electrodes;
c) first and second conductive elements on said insulating means and extending therefrom so as to be in electrical contact, respectively, with said opposed electrodes;
d) third and fourth conductive elements on said insulating means and extending therefrom towards said arrestor; and e) two devices each having the capability of limiting current flowing therein to have an amplitude which is no greater than a predetermined amplitude, one of said devices in contact with said first and third conductive elements to provide a conductive path therebetween and the other of said devices in contact with said second and fourth conductive elements to provide a conductive path therebetween.
2. The line protector of Claim 1 wherein each of said devices are leadless and have a resistance which increases substantially in magnitude when the temperature of said device rises to a predetermined temperature above ambient temperature.
3. The line protector of Claim 1 wherein said surge voltage arrestor has an electrode intermediate said opposed electrodes and said line protector further comprises a fifth conductive element extending from said insulating means and connected to said intermediate electrode.
4. The line protector of Claim 1 wherein each of said devices has opposed conductive faces, said opposed conductive faces of one of said devices in contact with said first and third conductive elements, respectively, and said opposed conductive faces of the other of said devices in contact with said second and fourth conductive elements, respectively.
5. The line protector of Claim 1 wherein said surge voltage arrestor is of the spark gap type.
6. A line protector for a communications circuit comprising:
a) a base having first and second line input terminals therein and first and second equipment terminals therein;
b) an overvoltage arrestor in spaced relationship to said base, said arrestor having first and second electrodes;
c) first and second conductive means secured to said first and second line input terminals, respectively, and extending therefrom so as to be in electrical connection with said first and second electrodes, respectively;
d) third and fourth conductive means secured to said first and second equipment terminals, respectively, and extending therefrom towards said overvoltage arrestor; and e) two devices each having the capability of limiting current therein to have an amplitude which is no greater than a predetermined amplitude, one of said devices in contact with said first and third conductive means to provide a conductive path therebetween and the other of said devices in contact with said second and fourth conductive means to provide a conductive path therebetween.
a) a base having first and second line input terminals therein and first and second equipment terminals therein;
b) an overvoltage arrestor in spaced relationship to said base, said arrestor having first and second electrodes;
c) first and second conductive means secured to said first and second line input terminals, respectively, and extending therefrom so as to be in electrical connection with said first and second electrodes, respectively;
d) third and fourth conductive means secured to said first and second equipment terminals, respectively, and extending therefrom towards said overvoltage arrestor; and e) two devices each having the capability of limiting current therein to have an amplitude which is no greater than a predetermined amplitude, one of said devices in contact with said first and third conductive means to provide a conductive path therebetween and the other of said devices in contact with said second and fourth conductive means to provide a conductive path therebetween.
7. The line protector of Claim 5 wherein each of said devices are leadless and have a resistance which increases substantially in magnitude when the temperature of said device rises to a predetermined temperature above ambient temperature.
8. The line protector of Claim 6 wherein said overvoltage arrestor has a third electrode intermediate said first and second electrodes and said line protector further comprises a ground terminal in said base and extending therefrom to be connected to said third electrode.
9. The line protector of Claim 6 wherein each of said devices has opposed conductive faces, said opposed conductive faces of one of said devices in contact with said first conductive means and said third conductive means, respectively and said opposed conductive faces of the other of said devices in contact with said second conductive means and said fourth conductive means, respectively.
10. The line protector of Claim 6 wherein said surge voltage arrestor is of the spark gap type.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/281,492 | 1988-12-08 | ||
| US07/281,492 US4876621A (en) | 1988-12-08 | 1988-12-08 | Line protector for a communications circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1331479C true CA1331479C (en) | 1994-08-16 |
Family
ID=23077531
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000609187A Expired - Fee Related CA1331479C (en) | 1988-12-08 | 1989-08-23 | Line protector for a communications circuit |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4876621A (en) |
| CA (1) | CA1331479C (en) |
Families Citing this family (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5008772A (en) * | 1990-09-24 | 1991-04-16 | Porta Systems Corp. | Telephone circuit protector module having plural circuit grounding means |
| US5155650A (en) * | 1991-08-21 | 1992-10-13 | Adc Telecommunications, Inc. | Thyristor fail-safe |
| US5175662A (en) * | 1991-08-30 | 1992-12-29 | At&T Bell Laboratories | Device including an MTU and protector |
| US5237483A (en) * | 1991-10-01 | 1993-08-17 | Reliance Comm/Tec Corporation | Protector system for low voltage power feed |
| US5359657A (en) * | 1992-06-08 | 1994-10-25 | Oneac Corporation | Telephone line overvoltage protection apparatus |
| CA2095500C (en) * | 1992-06-08 | 1997-09-23 | Dimitris Jim Pelegris | Telephone line overvoltage protection method and apparatus |
| US5369543A (en) * | 1992-08-13 | 1994-11-29 | Adc Telecommunications, Inc. | Thyristor fail-safe device |
| FR2704380B1 (en) * | 1993-04-23 | 1995-06-09 | Pouyet Int | PLUGGABLE PROTECTION MODULE FOR QUICK INTERCONNECTION MODULE OF TELEPHONE LINES. |
| DE4317191B4 (en) * | 1993-05-22 | 2004-02-05 | Dehn + Söhne GmbH + Co KG | Process for creating an arrangement for protecting a device against overvoltages |
| US5541804A (en) * | 1994-07-11 | 1996-07-30 | Illinois Tool Works Inc. | PTC protector for AT&T style 110 block |
| US6188560B1 (en) | 1994-10-21 | 2001-02-13 | 3M Innovative Properties Company | Multi-wire terminal block employing removable surge protector |
| DE19615729B4 (en) * | 1996-04-20 | 2005-02-17 | Dehn + Söhne GmbH + Co KG | Overvoltage protection arrangement for protecting a terminal against overvoltages, as well as methods for creating an overvoltage protection arrangement |
| US6222717B1 (en) | 1997-05-15 | 2001-04-24 | 3M Innovative Properties Co. | Multi-chamber telecommunications terminal block with linking module |
| US5880919A (en) * | 1997-06-24 | 1999-03-09 | Siecor Corporation | Gas tube surge protector with interacting varistors |
| US6084761A (en) * | 1998-03-09 | 2000-07-04 | Teccor Electronics, Lp | Telephone line surge protector |
| US6104591A (en) * | 1998-03-09 | 2000-08-15 | Teccor Electronics, Inc. | Telephone line protection element |
| US6980647B1 (en) | 1999-01-12 | 2005-12-27 | Teccor Electronics, Lp | Primary telephone line protector with failsafe |
| US6956248B2 (en) | 1999-03-01 | 2005-10-18 | Teccor Electronics, Lp | Semiconductor device for low voltage protection with low capacitance |
| US6531717B1 (en) | 1999-03-01 | 2003-03-11 | Teccor Electronics, L.P. | Very low voltage actuated thyristor with centrally-located offset buried region |
| US6249416B1 (en) * | 1999-06-22 | 2001-06-19 | Avaya Technology Corp. | Grounding device for voltage surge protection of telecommunications equipment |
| US6259590B1 (en) * | 1999-06-22 | 2001-07-10 | Avaya Technology Corp. | Grounding device for preventing lorentz force in voltage surge protection |
| US6385030B1 (en) | 1999-09-02 | 2002-05-07 | Marconi Communications, Inc. | Reduced signal loss surge protection circuit |
| US6204746B1 (en) * | 1999-09-13 | 2001-03-20 | Avaya Inc. | Thermal overload mechanism |
| US6396673B1 (en) | 1999-10-08 | 2002-05-28 | Marconi Communications, Inc. | Reduced-loss, high-frequency signal transmission system utilizing an over-voltage and over-current protection device |
| US6814631B2 (en) * | 2002-04-02 | 2004-11-09 | Marconi Intellectual Property (Ringfence) Inc. | Electrical terminal for surge protection cartridge |
| US20050099755A1 (en) * | 2003-11-10 | 2005-05-12 | David Martin | Broadband surge protector with non-resetting current limiter |
| AU2006208074B2 (en) * | 2005-01-27 | 2010-06-10 | Adc Telecommunications, Inc. | Loop plug |
| US7175471B1 (en) * | 2006-04-21 | 2007-02-13 | Adc Telecommunications, Inc. | Loop plug |
| JP5248374B2 (en) * | 2009-03-13 | 2013-07-31 | 新光電気工業株式会社 | 3-pole surge arrester |
| US20140118102A1 (en) * | 2012-10-29 | 2014-05-01 | Sean Iwasaki | Telecommunication surge protector system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3849750A (en) * | 1974-01-02 | 1974-11-19 | Reliable Electric Co | Line protector for a communication circuit |
| US3975664A (en) * | 1975-07-28 | 1976-08-17 | Reliable Electric Company | Line protector for communication circuit |
| NL8006411A (en) * | 1980-11-25 | 1982-06-16 | Philips Nv | DEVICE FOR PROTECTION AGAINST OVERHEATING BY OVERVOLTAGE OF A VOLTAGE LIMITING CIRCUIT. |
| FR2600465B1 (en) * | 1986-06-18 | 1993-09-03 | Citel Cie Indle Tubes Lampes E | PROTECTION AGAINST OVERVOLTAGES ON TELEPHONE LINES OR INFORMATION TRANSMISSION LINES OR THE LIKE |
-
1988
- 1988-12-08 US US07/281,492 patent/US4876621A/en not_active Expired - Lifetime
-
1989
- 1989-08-23 CA CA000609187A patent/CA1331479C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| US4876621A (en) | 1989-10-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1331479C (en) | Line protector for a communications circuit | |
| US4907120A (en) | Line protector for a communications circuit | |
| CA1067953A (en) | Line protector for communication circuit | |
| CA2809020C (en) | Pluggable metal oxide surge arrester | |
| US5359657A (en) | Telephone line overvoltage protection apparatus | |
| US4086648A (en) | Protector module | |
| HU206796B (en) | Protective circuit and protective terminal for protecting consumer against overvoltage and overcurrent | |
| US4161762A (en) | Gas tube arrester protector and method of assembling the protector | |
| EP0018067A1 (en) | Line protector for a communications circuit | |
| US4613732A (en) | Interface module with modular jack for telecommunications systems | |
| US4723190A (en) | Safety device communication equipment | |
| US3818271A (en) | Line connector for a communications circuit | |
| US5500782A (en) | Hybrid surge protector | |
| US5027100A (en) | Gas tube fail safe device for telephone protector modules | |
| US4424546A (en) | Miniature central office surge protectors | |
| CA2066048C (en) | Solid state telephone protector module | |
| US4071872A (en) | Interrupter | |
| US6204746B1 (en) | Thermal overload mechanism | |
| US5398152A (en) | Overvoltage protector | |
| US4527215A (en) | Valve type voltage arrester device | |
| US5008772A (en) | Telephone circuit protector module having plural circuit grounding means | |
| EP0183542A1 (en) | Circuit protection arrangement | |
| US4910489A (en) | Gas tube fail-safe device for telephone protector modules | |
| US4075676A (en) | Interrupter | |
| EP0657978B1 (en) | Failsafe device for use with electrical surge suppressor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |