GB2277127A

GB2277127A - Igniter construction

Info

Publication number: GB2277127A
Application number: GB9413907A
Authority: GB
Inventors: Leroy B Adam; Steven J Cannady; Darin W Carr; William B Meeks; Michael A Runge; Jan R Schueren; Stephen W Straub
Original assignee: Cooper Industries LLC
Current assignee: Cooper Industries LLC
Priority date: 1990-03-09
Filing date: 1994-01-24
Publication date: 1994-10-19
Anticipated expiration: 2011-02-22
Also published as: GB2273612A; GB9413807D0; GB2277127B; GB9413907D0; GB9401307D0; GB2277212A; GB9414007D0; GB2277212B; GB2277414A; GB2277414B; GB2273612B

Description

2277127 1 IGNITER CONSTRUCTION This invention relates to gas turbine

engine igniters and more particularly to an 4=proved igniter and cable connector assembly and to an improved terminal structure for an igniter and igniter cable connector.

igniters f or use in aircraft turbine engines are typically formed with a metal shell surrounding an insulator. The shell is threaded to engage a threaded igniter cpening in the engine. A high voltage terninal is recessed well within a free end of the insulator. A mating high voltage cable connector has a projecting insulator which supports a terminal. The connector insulator extends Well into the igniter insulator establish a long flashover path between the high voltage terminals and the grounded igniter shell. This construction results in a large prof ile for prior art ignitor and cable connec=or assemblies. When one comr.cn prior art cable connector is secured to an igniter, t..e cable insulator projects into the igniter insulator and a spring In the cable c--.-, nector presses the cable tern. inal against the igniter terminal to establish a -age connection. Typically, contact between high volt terminals takes place cn'y at a point or over a small surface area. An appropriate annular seal is located between the igniter and t.&e cable connector to keep contaminants from entering the space between the ignitar and connector insulators. A separate spring may be provided In the connec=---- to compress the seal against the igniter. Any c--nta=-4nants entering the terminal region =av result in igniter failure due to flashover. Ideally, the seal also will prevent air from escaping from the space surrounding the terminals when the igniter is operated at high altitude. As the air pressure across a gap decreases, the flashover voltage required to jump the gap also decreases.

11 2 There are many problems with the design of present state of the art igniters and igniter cable connectors. The large number of component parts in aviation engine igniters and igniter cable connectors results in a high manufacturing cost, a large profile and an excessive weight. There is difficulty in establishing and maintaining a good seal between the igniter and the connector and in maintaining a good electrical contact between the igniter and the connector terminals.

operating failures can occur at the seal and also at the contact point between the high voltage connector terminal and the igniter terminal. Any arcing between the terminals caused by poor surface contact will eventually lead to igniter or cable failure.

is 1-1- 4on-is directed to an improved .e 'Dresent inventJgniter and to an improved igniter and cable connector assembly for turbine engines. A threaded igniter adaDtar is secured to an igniter hole in the engine.

The igniter slides through a hole in the adapter to ion the spark gap cn the igniter at the proper positlocation in the engine combustion chamber. An enlarged A. - W - diameter head on the igniter is retained by the adapter. An annular seal IA.S positioned on the igniter head to 25encircle a high voltage terminal projecting from the igniter head. A spring loaded terminal on a cable connectC.- extends thrOuch the center of the seal and is Pressed against the igniter terminal when the cable connector is attached to the adapter. 'When the cable conneczor _4S secured to --he adapter, t..e seal is compressed between connector and igniter insulators.

Ihe cable connector =ay be secured to the adapter by, for example, either by a hinged clamp which engages conical surfaces on the adapter and the cable connector or by a coupling nut on the cable connector which is threaded onto the adarter or by a quick connect mechanism on one of t.Ae connector or the adapter for 1 0 3 releasably engaging an annular groove on the other of the connector or the adapter. In a modification of the invention, a quick connect mechanism on theigniter cable connector releasably engages an annular groove 5 formed on the igniter.

As the connector is secured to the adapter,, the igniter terminal is pushed in an axial direction against the f orce of a spring in the cable connector. At the same time, threads between the connector insulator and terminal cause the connector terminal to rotate about its axis to establish a good electrical contact with the igniter terminal. Preferably, ths igniter and connector te=inals are fo=ed with mating conical or spherical surfaces, one of which is an annular segment having a void in the center to allow any surface contaminants between the contacting surfaces to escape. The terminal shape provides a wide line or surface contact extending around the axis of the terminals. This is an i=7rovement over point or small area contact produced by 420 many prior art terminal designs where flat or convex surfaces meet.

Mis improved igniter and cable connector assembly has several advantages over prior art assemblies. The annular seal provides.4=vroved flashover protection.

The rotation of Ithe ccnnector terminal as it is pressed against the igniter terminal provides improved electrical contact. The igniter construction is less expensive to manufacture and weighs less than prior art ince it recru-, igniters s res less parts, has a smaller :30 proff-I's and is simpler to manufacture. Further, the igniter adapter whic!". 4s secured to the engine need not be removed from the engine or replaced when replacing the igniter.

Accordingly, it is an object of the invention to provide an improved igniter and cable connector assembly suitable for aviation engines.

4 other objects and advantages of the invention will be apparent from the following detailed description and the accompanying drawings, in which:

Fig. 1 is a side elevational view of an igniter and cable connector assembly according to a first embodiment of the invention; Fig. 2 is an enlarged vertical cross sectional view through the igniter and cable connector assembly of Fig.

1; Fig. 3 is a side elevational view of the turbine engine mounting adapter from the assembly of Fig. 1; 4 is a side ellevational view of the igniter from the assembly of Fig. 1; Fig. 5 is a perspective view showing the igniter and"ca-le connector clanD assembly in an open position; 21g. 6 is an enlarged fragmentary top plan view showing an exemplary latch for securing the clamp asser.bly of Fig. 5; F-4g. 7 is an e nlarced fragmentary vertical cross sectic-nal view through an igniter and cable connectcrasserizzly according to -1 zodified embodiment of the invention; Fig. 8 is an enlarged fragmentary cross sectional view shc.wing details c. he igniter and cable connec----r terminals according to a modified embodiment of the invent-4on; is an enlarged fragmentary cross sectionnall view s.-.ow.:&.ng details c-' the igniter and cable connector 0 - a further mod-4-,'-4ed embodimenz c.

0 ter-minals according to -h on; .e invenzi Ficr. 10 is an enlarged fragmentary cross sectiona view through an igniter and cable connector assembly according to a further modified embodiment of the 35 invention; and F.4hg. 11 is an enlarged fragmentary cross sectional view thrcugh an igniter and cable connector assembly A 0 according a still further modified embodiment of the invention.

Referring to Figs. 1 and 2 of the drawings, an igniter and cable connector assembly 10 is illustrated according to a first embodiment of the invention. The assembly 10 includes an igniter 11. an engine mounting adapter 12.2 and a high voltage exciter cable connector 13. A clamp 14 secures the connector 13 to the adapter 12. M4e clamp 14 has two halves 15 and 16 which are secured tOgether by a suitable latch 17. A wire or split r4ng iS prevent accidental opening of the latch '1 7.

The adapter 12 14s shown in detail in Figs. 2 and 2.

The adapter 12 is generally tubular, having an axial opening 19 extending between a lower end 20 and an upper "he adapter 12 has exterior - end 21. 1 -1hreads 22 for securing thhe adapter to a threaded igniter opening in, an engine (not shown). A hexagonal nut 23 is integrally formed on It-ne extericr of the adapter 12 adjacent C'le upper end 21 for receiving a suitable wrench (not shown) when securing the adapter to or removing the adapter from an engine. Either a conical surface 24 below the 4- '1 or the lower adauter end 20 may be located tC i.hreads 2 seat against a mating surface in the engine to forn. a gas seal. or, a suitable gasket may be placed on the surface 24. Between the threads 22 and the nut 23, a reduced diameter ar-.cve z25 is for--ed around the adazter!:. The a=ve:S has a conical upper surface :0 Z6 which. faces downwar,-Iv and outwar-ly.

1.azails of the ignizar 211 are s.I-Acwn in Fics. 2 and The ianiter 11 has a tubular shell or sheath 29 extending between a lower or first end 30 and an upper or second end 31. At the upper end 31, the metal 325 forming the sheath 29 forns an enlarged diameter head 32. Mhe sheath 29 has a diameter for a close sliding fit in the adapter opening 19, while the head 32 abuts -2.

6 against the upper adapter end 21. The sheath 29 has a stepped axial bore 33 for receiving a ceramic insulator 34. The insulator -14 has a tubular body portion 35 of a diameter for being received by the sheath bore 33. At a lower end 36, the insulator 34 is seated against the sheath end 30. The insulator 34 also has an enlarged diameter head 37 which abuts and overlays at least a portion of the sheath head 32. If desired, the sheath head 32 =ay wrap around at least a portion of the perimeter of the insulator head 37 to protect the insulator head 37 from damage. A fused glass seal 38 is located between the heads 32 and 37 to retain the,nsulator 34 in the sheath 29 and to prevent combust4cn gases fro= leaking betueen the insulator 34 and the sheat., The insulator 34 has an axial bore 39 in which a center electrode 40 is secured by a fused glass seal 41. '"he seal -21 also prevents combustion gases from leaking between the center electrode 40 and t-he insulator bore 39. The center electrc-die 40 has a lower end 42 which is spaced from the sheat.-. and 30 to fo= a spark gap. The -he center electrode 40 terminates at a upper and of 16.

age igniter te=inal 43. The terminal 43 high volt 16 nsulator head projects above a top surface 44 on td&e -4 37. As illustrated, the terminal 43 may have an upwardly and outwardly directed conical shape. From t..e -- w411 be apparent to those skilled above description, I..1. -

4n the art that the ignit-er 11 is highly simplified over -r;or art turbine enc4ne "ypically, the pr- - !r' Z- igniters. PA 4c art iznitars include a large shell ranufactured from 4=-,e par- eferent 4- =ult %.s and several dif -sulator compc.nents. The simpli,"ed construction significantly reduces the manufacturing cost for the igniter 11.

74g. 2 shows a cross section through an end of the igniter exciter cable ccnnector 13. The connector 13 includes a shell 47, a ceramic insulator 48 and a high voltage electrode 49 which terminates at a terminal 50.

7 The shell 47 has an enlarged diameter portion 51 terminating at an end 52 against which an enlarged diameter end 53 on the insulator 48 abuts. The enlarged diameter shell portion 51 has an upwardly and outwardly facing conical exterior surface 54 which is used to secure the connector 13 to the adapter 12. as will be discussed below. The electrode 49 is mounted in a bore:o reciprocate in an axial in Ithe insulator 48 t direction. A spring 56 located in the insulator bore -95 is co=pressed between a washer or pin 57 attached to the electrode 49 and a stat4onary sleeve 58. The spring 56 presses downwardly on the electrode 49 to extend the t 50 from the insulator bore -95.

-erminal 5 When the connector 13 is secured to the adapter 12. the spring 56 presses the cc-nnect-or ter=inal 50 against the igniter terminal 43. As the c=nector 13 and the igniter 11 are brought together, the electrode 49 moves in an axial directicn into the insulator bore 55, sliding in a contact 59 connected zz a high voltage wire in an 1 exciter cable (not shown) As is discussed below, 1...e electrode 49 preferably also is mounted in the insulatcr bore 5-1 Itc be slightly r-- zated as it Js reciprocated in an axial direction.

The clamp 14, which. is shown in Frigs. 2 and 5, secures the cable connector 13 to the adapter 12. A hinge 60 connects one edge of the clamp halves 15 and 16.ogether to pivot between an open position as shown Fig. 5 and a closed pcs.'z4-n as shown in Fig. 2. When - - -.1. - W the c2.-==p 14 _Js cIcsed, the latch 17 secures together cpen eges 61 and 62 c.-0 the clamp halves 15 and 16 respecz4,.ely. The cia== 1-4 has a stepped axial bore -5-- havina a llower end 64 -'ocr fitting into the adapter groove 25, a central portion. 65 for enclosing the head end on the igniter 11 and the enlarged end on the connector 13, and an upper end 66 for passing the connector shell 47. A c. -nical surface 67 is located between the lower bore end 64 and the central bore a portion 65 and a conical surface 68 is located between the central bore portion 65 and the upper bore end 66. The conical surface 67 -4s positioned and shaped to engage the conical adapter surface 26 and the conical surface 68 is positioned and shaped to engage the conical connector shell surface 54.

Details of an exemplary construction for the clamp latch 17 are shown in Fig. 6. The latch 17 has a first a= member 71 which is attached at an end 72 to a tab 73 on the clamp half 16 by a pivot pin 74. A second arm member 75 is pivotally attached near its center to an opposite end 76 of the member 71 by a pivot pin 77. The member 755 has a taDered end 78 which engages a bracket 79 on '1621,1e clamp half 15. A free end 80 on the member 75 serves as a lever for cpening and closing the latch 17.

When the latch 17 is closed, a bracket 81 on the clanip extends throuah half 4-he member and a wire or a split ring 82 is passed through a hole 83 in the bracket 81 to prevent accidental opening of the latch 17. It will be appreciated by those skilled in the art that other types of latches may be used for releasably securing together %.he edaes 61 and 62 clamp halves 15 and 16.

Referr_4ng again to Fig. 2, the igniter 11 is installed in an engine and the cable connector 13 is attached by first installing the adapter 12 in a threaded igniter opening in the engine. The igniter 11;s than slid into the adapter opening 19 until the sheath. head 32 abuts the adapter end 21. Next, an annular resilient seal! 64 is positioned around the head 30 of the igniter 11. The seal 84 has a tubular lower end J ter S5 wh1c.h surrounds at ieast the periphery of the ign-insulator head 37 and -,.av also surround the periphery of the sheath head 32. An integral flange 86 on the seal 84 extends radially inwardly over a portion of the top insulator surface 44 to surround the terminal 43. The seal 84 also has a tubular upper end 87 which receives and engages the periphen, of at least the connector 9 insulator end 53 and may also extend around a portion of the enlarged connector shell portion 51. The seal 84 is formed from a suitable high temperature resilient rubber like material. In the past, Igniter connector seals have been constructed from a silicon rubber which Is capable of withstanding operating temperatures of up to 450F. However. according to a prefe=ed embodiment of the invention. the seal is made from, Kalrez (m) manufactured and sold by E. I. Dupont de Nemours & Cc.

lc) whic.n. can function at up to 6000F.

After the seal 84 lls positioned over the igniter insulator head 37. the connector 13 is positioned adjacent the igniter 11 with the insulator end 53 within the upper tubular seal end 87 and the -connector ter=inal 50 contacting the igniter terminal 43. The open clamp 14 is positioned around the adapter 12 and connector 13 to extend into the adapter groove 25 and over the conical connector surface 54. As the clamp 14 is the conical clamp surface 67 engages the conical closed, t adapter surface 26 and the conical clamp surface 68 engages the conical connector surface 55.4. The conical surfaces press the connector 13 axially toward the igniter!h as the clamp 1.4 is closed. At the same t- 4=e, the seal flange 86 is cc=pressed between the connector insulator end 53 and the top surface 44 on the igniter insulator 37 to form a t4ght seal surrounding the terminals 43 and 5550. T.he lower seal end 85 also is compressed between the periphery of the igniter insulator head 37 and the wall of the central portion 65 0 of the cl-amp bore 63 and the upper seal end 87 is compressed between the periphery of the connector insulator end 53 and the wall of the central portion 65 of the clamp bore 63. Thus, three separate annular sealing areas are produced when the clamp 14 Is closed.

The latch 17 is engaged to complete closure of the clamp 14 and Che split ring IS is installed to hold the clamp 17 closed.

Referring now to Fig. 7, an igniter and cable connector assembly 90 is illustrated according to a modified embodiment of the invention. The assembly 90 includes an adapter 91 for securing to an engine (not shown), an igniter 92 mounted in the adapter 91. and a connector 93 for attaching an exciter ignition cable (not shown) to the igniter 92. The adapter 91 has an externally threaded lower end 94 which is sized to engage a conventional threaded igniter opening in an engine. A hexagonal section 95 is formed on the adapter above the threaded end 94 to receive a suitable wrench when securing the adapter 91 to or removing it from the engine. Adjacent an upp-ar end 96, the adapter 91 has an externally threaded section 97 for receiving a coupling nut 98 on the connec4.-cr 93. The adapter 91 is tubular shaped and has a stepped axial bore 99 having a larger diameter upper secticn 100 and a smaller diameter lower section 101.

T 4gniter 92 - 1.e of similar construction -ay Ithe igniter 11 illustrated in Figs. 2 and 4. The igniter 92 has a body 1C.2 having an exterior diameter:h for s',..'d-4ng into and closely engaging the walls of a lower adapter bore section 101. At a lower end 103, the ',.gniter defines a recessed spark gap. At an opposite upper end, the igniter 92 has an enlarged diameter head 104 including a flange Ilw15 which abuts an end wall 106 of the adaDter bore section 100 to retain the igniter 92,n th.e adapter bore 99. A high voltage terminal 107 projects above an insulator section 108 which overlays at least a portion of the flange 105.

n annular seal 09 Js positioned over the ign.'zer head 104. The seal 109 has a stepped bore 110 which. confor= to at least the insulator section 107 and surrounds the terminal 108. The seal bore 110 also confor=s to a lower end 115 of an insulator ill and to a ' on the connector 93. The seal high voltage terminal 11. may be made from any suitable resilient material which 11 will resist the operating temperatures present between on the igniter 92 and the connector 93. such as a silic. rubber or. preferably, Kalrez (TM).

The connector 93 has a tubular shell 113 with a bore 114 in which the insulator 111 is mounted. Either the, insulator 111 and the terminal 112 are mounted to reciprocate together In an axial direction relative to the shell 113 or, preferably. the terminal 112 Is mounted to axially reciprocate In the insulator 111. as is known in the prior art. As is discussed below, the terminal 112 is preferably mounted to rotate as it reciprocates in the insulator 111. Adjacent the lower.end 111.5 of the insulator Ill, the shell bore 114 has an enlarged diameter section 116. The seal 109 is compressed to fill the chamber between the shell bore sectJon 116, the insulator end 115, the terminals 103 and 1.1.2 and the igniter head 104.

The connector shell 113 has an enlarged diameter radial flange 117 which retains the coupling nut 98.

The coupling nut 98 has an internally threaded secz.400n 113 which engages the threaded section 97 on the adapter 91. An exterior surface 119 on the coupling nut 98 =ay be shaped to receive a wrench (not shown) for securing the coupling nut 98 tc and removing it from the adapter 91. 'When the connector 93 is inserted Into the adapter 91 and the coupling nut 98 is tightened, an end 1.20 on W..Ae shell 113 presses against the igniter flange 105 to tightly hold the igniter 92 in the adapter 91 and ccnnec-..-#r terminal 11.12 is pressed jE-4=ly against '20 igniter terminal IC)S.

Fig. 2 illustrates an igniter 11 having a tar--.4..al 43 in t.he shape of an upwardly and outwardly facing cone and a connector having a terminal 50 with an end surface in the form of a conical segment which makes a ring 35 contact around the axis of the igniter terminal 43. Figs. 3 and 9 illustrate additional preferred embod=ients of the configuration of the igniter and 12 connector terminals. Fig. 8 shows a fragmentary portion of an igniter 123 having a terminal 124 and a fragmentary portion of a connector 125 having a terminal 126. The connector terminal 126 is mounted to reciprocate in an insulator 127 against the force of a spring 128. According to the invention, one or more mating threads 129 are formed between the insulator 127 and the terminal 126. The threads 129 are coarsely formed to impart a limited amount of rotation to the terminal 126 as it is reciprocated in the insulator 127.

This rotation produces a wiping action between the 12 A terminals 126 and x as the connector 125 is secured to the engine adapter and the terminal 126 is pressed into the insulator 127. r-r-..e wiping action establishes a more posit4ve electrical contact between the terminals 124 and 126. Only slight rotation of the terminal 126 is effective, for example, a rotation of less than 900 is effective. It should be appreciated that the terminal 50 in Frig. 2 may be -zounted to rotate in a similar manner as it is reciprocated.

The mating surfaces of "the te=inals 124 and 126 are preferably conical. The igniter terminal 124 has a contact surface 130 4Ln the form of an upwardly and inwardly facing conical segment with an open center 131. The connector terminal:26 has a contact surface 132 in the f.-= of a downwardly and outwardly facing conical segment and has a flaz center 133. 'When the terminals -he surfaces 130 and 124 and 126 are pressed together, 46.1321 abut around the axis of the igniter 123 and :0 ccnnect--r 122.5 to fc--- a continuous contact around a conical segment defined by the surface 130. Rotation of the connector terminal 1- 226 as contact is established between the terminals 12.4 and 126 causes any minor surface contaminants such as small particles of dirt either to escape into t..e center opening 131 or to move outwardly from the contacting surfaces. This -ively provides a greater and more positive effect i electrical contact area than is achieved in prior art igniter and cable connector assemblies. In many prior art connectors, contact is achieved at only a point or over a small area. Surface dirt may prevent direct surface contact, which will initially result in small arcing between the adjacent surfaces. Any such arcing may lead to eventual failure of the igniter.

Fig. 9 shows a further modification in which a terminal 134 is mounted to axially reciprocate and to 10rotate in a connector insulator 135 and a terminal 136 is mounted on an igniter 137. The connector terminal 134 is provided with a convex spherical end surface 138 which contacts a concave spherical end surface 139 an the igniter terminal 136. An opening 140 is provided in the center of the concave igniter terminal surface 139 to allow any surface dirtand contaminants to escape from t..e contact area. The terminals 134 and 136 are shaped to obtain electrical contact over a spherical segment extending around the axes of the igniter 137 and the connector 135.

Fig. 10 is an enlarged fragmentary cross sectional view showing a furt. 4er =%Idified embodiment of an igniter and cable connector assembly 143 according to the 4nvention. In the asserioly 143, a cruick release mechanism 144 is used -"%-c secure an exciter cable connector 145 to an adarter 146. The quick release mechanis= 144 may be located either on the connector 145 or on the adapter 1146, although it is shown on the adapter 146 in Fig. 10. The quick release mechanism 144 can be cf a const-ructicn similar to quick release hose connectors and permdt's easy attachment and removal of the connector 145 wit.1-4out "Che need for tools. The au.4ck release =echanism 144 is strong and reliable.

The adapter 146 has an externally threaded lower end 147 adapted to engage a threaded igniter opening in an engine (not shown). A hexagonal section 148 is formed above the threaded end 147 for engagement with a 0 14 suitable wrench when installing the adapter 146 in or when removing the adapter 146 from an engine. A stepped bore 149 extends axially through the adapter 146. The bore 149 has a smaller diameter lower end 150 for passing the body 151 of an igniter 152 and an enlarged diameter upper end 153 for retaining a head end 154 on the igniter 152.

Adjacent an upper end 155, the adapter 146 has a predetermined diameter exterior section 156. The.

adapter 146 has a slightly larger diameter exterior section 157 between the section 156 and the hexagonal section 148. At least three tapered holes 158 are formed in the adapter section 156 to lie in a plane perpendicular to the axis of the upper bore end 153. A ball 159 is located in each hole 158. Each ball 159 has a diameter greater than the wall thickness of the adapter section 156. The balls 159 and holes 158 are sized such that the balls 159 may extend through the holes 158 into the bore end 153 while they are restrained from passing totally through the holes il-E into the bore end 1.53. A spring loaded tubular sleeve -4s positioned to s14,.de on the adapter 146. The sleeve 160 has an interJor section 161 which slides on the exterior adapter section 156 and an interior sect4on 162 which slides on the exterior adapter section 157. A spring 163 is located in a chamber 164 between the sleeve section 162 and the adapter section 156. The spring 163 presses the sleeve 160 in an upward axial direction against a retainer ring 165 which engages the adapter exterior secz4icn 156 between the tapered holes 158 and the adapter end 155. While the sleeve 160 is held In its normal up position against the retainer ring ---heinterior SeC4 165, t -_4cn 161 on the sleeve 160 is positioned over the balls 159 to hold the balls 159 in a position wherein they extend into the adapter bore section 153. The sleeve 160 may be moved downwardly in an axial direction against the spring 163 by manually R is grasping and pushing on a knurled exterior surface 166 until a sleeve end 167 abuts a stop 168 on the adapter 146. In this position, an enlarged interior diameter area 169 in the sleeve 160 permits the balls 159 to retract from the bore section 153 into the holes 158.

The connector 145 is attached to a free end of a high voltage cable 170 from an exciter (not shown). The connector 145 includes a shell 171 having an exterior diameter for sliding in an axial direction into-and for closely engaging the walls of the upper adapter bore section 153. An annular groove 172 is formed in the shell 171 at a location for receiving the balls 159 when the connector 145 is secured to the adapter 146. The connector 145 is secured to the adapter 146 by moving the sleeve 160 against the spring 163 until the balls 159 can retract from the upper bore adapter end 153, inserting the connector 145 into the upper adapter bore end 1-,--3 and releasing the sleeve 160 to force the balls 159 into the connector aroove 172. The balls 159 retain the connector 145 in the adapter 146 until the sleeve 160 is moved to allow the balls 159 to retract from the groove 172.

The remaining internal construction of the connector 145 may be similar to the construction of t..e connector 93 described above. The connector 145 has an internal insulator 1731 which mounts a high voltage terminal 174 for axial and preferably also for 4- -or 145 is secured -o rotat nal movement when the connect the adapter 146. The ccnnector terminal 174 is pressed against a center electrode terminal 17-9 projecting 41--cm the ignilter head 154. The terminals 174 and 175 preferably have aconstruction as shown for the terminals in any of Figgs. 2-. a or 9. A resilient annular seal 176 extends around the terminals 174 and 175 and is compressed between the igniter head 154 and the connector insulatiDr 173, between the igniter head 16 154 and the adapter bore end 153, and between the connector insulator 173 and the adapter bore end 153.

Fig. 11 shows an igniter and cable connector assembly 179 according to a further embodiment of the invention including a quick release exciter cable connector 180 secured dilrectly to an igniter 181. No adapter is used with the assembly 179. The igniter 181 has a shell 182 forming a lower end 183 for projecting into an engine combustion chamber, a threaded section 184 for engaging a threaded igniter opening in the engine and a hexagonal section 185 for engagement by a wrench (not shown). Above the hexagonal section 185, the igniter shell 182 has an enlarged diameter upper section 186 which includes an annular groove 187. An insulator 188 and a center electrode terminal 189 extend coaxially from the upper soction 186.

The connector 180 includes a shell 190 having a bore 191 sized to slide coaxially over and closely engaging the upper sect-4on 186 of the igniter shell 182.

An insulator 192 mounting a high voltage terminal 193 46s mounted in the shell 11842 for contacting the igniter terminal 189 when the c--nnector 180 is secured to the igniter 1-81. A resilient annular seal 194 fills the chamber around the te=-4nals 189 and 193 between the connector 180 and the igniter 181. The connector 180 has a quick release mechanism 195 which functions in a manner identical to the quick release mechanism 144 illustrated in Fig..1io. The mechanism includes a plurality of balls 196 pasitioned in tapered holes 197 in the connector she!! 1990 and a sleeve 198 for retaining the balls in the holes 197. The balls are positioned to engage the igniter shell groove 187 when the connector 180 is attached to the igniter 181. The sleeve 198 is normally =aintained in a locked position by a spring 199 which pushes the sleeve 198 against a retainer ring 200. Manually moving the sleeve 198 against Ithe spring 199 allows the balls to move into the W 1 17 holes 197 to install the connector 180 on and to remove the connector 180 from the igniter 181.

The above described embodiments of an igniter and cable connector assembly have several advantages over prior art assemblies. The assemblies are less expensive to manufacture, have a smaller profile and weigh less than prior art assemblies. Except for the igniter 181, there are no threaded connections an the igniter. once the adapter is attached to the engine, the igniter may be inserted and later replaced without removing or changing the threaded adapter. For the igniter and cable connector assemblies illustrated in Figs. 1. 2 and 10, no tools are recrui-red to replace the igniter. No gaskets are required for installing the igniter adapter on the engine. In the past, the threads on the igniters were silver plated to prevent seizure. No silver plating is required on the igniters of Figs. 1, 2 and 10 since there are no threads on the igniters. Further, the construction of the seal is more simplified and more effective at preventing flashover than seals in many prior art assemblies.

The design of the igniter also has several advantages over prior art igniters. The insulator and sheath designs are considerably simplified over prior art igniters. No internal tamped seals are required between a shell and the insulator or between the insulator and the center electrode. Nor is seal reaming requi.red since there are no tamped seals. The ceramic insulator is considerably simplified. Further, no :3 0 assembly gaging of "he various components is requi=ed as n the past.

it will be appreciated by those skilled in the art that various modifications and changes may be made in the above described preferred embodiments of the igniter :35 and exciter cable connector assembly and in the design of the igniter without departing from the scope of the following claims. For example, it will be 18 appreciated that the conical and spherical terminal constructions shown in Figs. 2, 8 and 9 and the means for rotating the connector terminals shown in Figs. 8 and 9 may be readily adapted to other igniter and connector designs. The quick release cable connectors shown in Figs. 10 and 11 also may be adapted to other connector and igniter designs.

The parent applications (9103707.7 & 9401307.5) of this divisional application are directed to an igniter and cable connector assembly comprising an adaptor and an igniter cable connector with a rotatable connector terminal, respectively. There are also corresponding divisional applications directed to an igniter and cable connector assembly with a conical or spherical segment contact area on one of the high voltage terminals and an igniter and cable connector assembly with a ball arrangement connecting the igniter and cable connector, respectively.

t_ 19

Claims

1. An igniter comprising a shell including a tubular sheath having first and second ends and an enlarged diameter head at said second sheath end, a tubular insulator mounted coaxially in a bore through said shell, and a seal bonded between said insulator and said shell, and a seal bonded between said insulator and said shell and extending completely about the axis, said insulator having an enlarged diameter head extending over at least a portion of said shell head, a center electrode mounted in a bore through said insulator, and a seal bonded between said insulator and said center electrode and extending completely about the axis, said center electrode having a first end forming a spark gap with said first sheath end and having a second end extending from said insulator head to form a terminal.

2. An igniter, as set f orth in claim 1, wherein said terminal has a conical contact surface.

3. An igniter, as set f orth in claim 2, wherein said conical contact surface is a conical segment.

4. An igniter, as set f orth in claim 1, wherein said terminal has a spherical contact surface.

5. An igniter, as set f orth in claim 4, wherein said spherical contact surface is a spherical segment.

6. An igniter, as set forth in claim 1, 2, 3, 4, 5 or 6, wherein the seal bonded between said insulator and said shell is of fused glass.

7. An igniter, as set forth in claim 1, 21 3, 4, 5 or 6, wherein the seal bonded between said insulator and said center electrode is of fused glass.