US2203784A

US2203784A - Ignition apparatus

Info

Publication number: US2203784A
Application number: US201057A
Authority: US
Inventors: Harry B Holthouse
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-04-09
Filing date: 1938-04-09
Publication date: 1940-06-11
Anticipated expiration: 1957-06-11

Description

June 11, 1940. H. B. HOLTHOUSE IGNITION APPARATUS Filed April 9, 1958 5 Sheets-Sheet l flf' Huh;

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IGNITION APPARATUS Filed April 9, 1938 3 Sheets-Sheet 2 fzyezzzr" i. flo/Z/wzme June 11, 1940. H. B. HOLTHOUSE 2,203,784

IGNITION APPARATUS Filed April 9, 1958 3 Sheets-Sheet 5 30 portant.

Patented June 11, 1940 umrso STATES PATENT OFFICE IGNITION APPARATUS Harry B. Holthouse, Chicago, Ill. Application April 9,1938, Serial No. 201,057 19 Claims. (01. 123-148) This invention relates toignition systems and has been illustrated as embodying various new structures as well as novel circuit features previously invented by me.

In my copending application Serial No. 741,610, filed August 27, 1934, (now Patent'No. 2,117,422, issued May 17, 1938) I have disclosed certain new ignition circuits which are characterized in part by the addition of a high frequency booster unit to the conventional ignition circuit. Ignition systems built in accordance with that invention have proved very advantageous. As an indication of the value of such a system, it may be noted that the spark generated thereby will jump a very much wider gap than will the spark of a conventional ignition system. Furthermore, the high frequency characteristics result in a very pronounced tendency to generate ozone, which is beneficial in producing ignition. It so happens, however, that both of these features, though very advantageous, make the voltage hard to handle. The higher voltage, or in general the tendency to jump wider gaps, means that extra precautions must be taken in adequately insulating the various terminals and contacts. The readily moldablp insulating materials such as Bakelite can have their surfaces transformed to a relatively conductive material by a current passing along the surface, and the prevention of this is very im- The ozone greatly aggravates the problem since it is chemically a very effective oxidizing agent, being ionized or separated from its molecular form to an atomic form which is very unstable, tending to combine with the first available substance.

A very important object of the present invention is accordingly to produce apparatus which will handle the high voltage and high frequency currents with complete satisfaction. 'Various de- 40 partures from prior practice are adopted in accomplishing this object. The terminals are adequately insulated, sometimes by the aid of grooves which elongate the surface path between the terminals. The distributor contacts are preferably adequately separated by similar grooves which, however, must be reduced to a very narrow width in the direction of rotation of the rotating contact to permit this contact to pass over them readily. There are preferably a plurality of the'narrow air gaps thus formed between each pair of the stationary contacts. The distributor also preferably includes provision for ventilation to avoid any high concentration of ozone. Under some circumstances the high frequency boosting unit works best when it is located immein my prior application mentioned and the present application is' therefore in part a continuation thereof in the nature of a division. 10

In other instances it is more desirable to include the boosting unit as a part of the main ignitioncoil unit, particularly when the combined units are to be substituted for the conventional coil already in use on an internal com- 15 bustion engine. One object of the invention is therefore to provide a satisfactory structure for this combination.

Another object of the invention is to provide the booster unit, or at least the secondary coil thereof, as a replaceable unit including a molded insulating housing. This secondary coil is the coil most likely to fail upon those rare occasions when something fails, and the ability to replace it readily is very advantageous.

The advantages and objects of the invention will be made more apparent by the following description and by the drawings, in which:

Fig. 1 is a sectional view of one combined dis-i tributor and booster coil unit constructed in ac- 30 cordance with this invention.

Fig. 2 is a plan view of the structure shown in Fig. 1 with the top removed therefrom and a portion of the rotor broken away.

Fig. 3 is a diagrammatic drawing of the circuit 35 kick coil are also included.

Figs. 8 to 10 illustrate other modified forms of combination distributor and high frequency coil, Fig. 8 showing one form adapted for use with the conventional spark coil, Fig. 9 showing a similar form with separable parts, and Fig. 10 show-. ing a form similar to that of Fig. 8 but. adapted for use with a mere kick coil. 55

Fig. 11 is a diagrammatic illustration of the circuit of Fig. 10.

Fig. 12 shows another preferred form of combination coil unit.

Fig. 13 is a bottom view of the top thereof.

Fig. 14 is a plan view of the supporting partition wall in the structure of Fig. 12.

Although this invention may take numerous forms, only a few have been chosen for illustration. All of the forms of the apparatus have been illustrated as specially adapted to handle very high voltages having high frequency characteristics. F'igs. l and 2 illustrate a combined timer, distributor, and high frequency booster coil having this qualification. I

Since the timer does not need to handle such unusually high voltages, it may be of conventional form and has been indicated by the spring contact arm in, contacts H and cam I! mounted on the shaft l3 which would of course be driven in timed relation with the motor, usually at half speed. Above the timer contact II the shaft ll passes through a distributor block H having therein a distributor cavity i6. On its upper end the shaft i3 carries a distributor rotor ll which has a rotating contact i8 which may be springurged as indicated against the stationary contacts is. The rotating contact ll or brush, as it may be called for convenience, is also connected through tube 2i and axial spring contact 22 with a contact 23 through which the high voltage current is supplied to the distributor to be distributed to the various spark plugs, which are of course connected to the stationary contacts ll through wires extending into terminal sockets 24. These wires may be held in place and in contact with studs formed'on the stationary contacts II by means of screws 25 which may be threaded into a bushing within the body ll if preferred. Of course, there are many other satisfactory ways of connecting such wires.

The contact 23 is carried by the bottom 28 of a housing 2'! which encloses a high frequency booster unit HF. This unit includes a primary winding 28 connected to the terminals 28 and a secondary winding 3i connected at one end to the contact 23 and at the other end to a terminal 32 formed in a socket 33 which is adapted to receive the lead wire from the conventional ignition coil. A pair of

condensers

34 and 35 are suitably mounted in any convenient position as on the metallic housing 35 of the timer unit. The advantage of this location is of course that the condensers will thus be grounded through the housing 36 to the engine block.

The ignition system for which the structure of Fig. l is particularly adapted is seen in Fig. 3.

' The battery t! may as usual be connected to ground and to a conventional ignition coil LF including the primary winding 42 and the secondary winding 43. This coil may be spoken of as the low frequency coil. The primary winding 42 will be connected to ground through the timer contacts i I which will be opened by the cam ii at the time ignition is desired. This will interrupt the flow of current in the primary winding 42 so that there will immediately be a high induced voltage in the secondary winding 43 and a high self-induced voltage in the primary winding 42. This latter voltage may for convenience be called the kick voltage. To keep the kick voltage from immediately sparking across the gap formed by the contacts Ii, it has been customary to provide a condenser 35 across these contacts so that the kick voltage would be absorbed by the condenser II. This condenser charge has always been wasted before my invention and. in fact, it has been worse than wasted since it would usually be discharged and thus produce a spark across the timer contacts II as they subsequently approached one another in closing. This spark was of course mainly, if not entirely, unidirectional, and the result was that the contacts H were eventually pitted by it or otherwise iniured.

According to my invention disclosed in my copending application previously mentioned, the kick voltage instead of initially being merely held in condenser 35 is discharged through a low frequency primary winding or coil 2| and a second condenser 34 which is also grounded. The coil 28, the condenser 34, and the timer contacts ll form a high frequency oscillating circuit so that a high frequency spark Jumps across the contacts I l instead of a low frequency spark. It has been found that this high frequency spark does not pit the contacts II. This alone is a great advantage of my ignition system but it is not the principal advantage.

The principal advantage involves the use of the high frequency secondary winding II which is in inductive relationship with the primary winding 28. This winding II, it will be noted, is interposed in series between the low frequency secondary winding 43 and the distributor rotor H. The result is that the high voltage induced by induction between winding 2| and winding 3| boosts the voltage of winding 43 so that a very high voltage is impressed across the gaps ll, representing the spark plugs. Furthermore, this voltage and the resulting spark have pronounced high frequency characteristics which are also advantageous. The winding 2| facilitates the discharge of condenser 34 so that the discharge, and the voltage boost, take place during the voltage surge of winding 43. It is thus seen that the kick voltage of coil l2 instead of being wasted and injuring the contacts II is utilized to produce better ignition and is changed so that it will not injure the contacts.

From the foregoing it will also be'evident, how ever, that the voltage supplied to the contact 23 and which must be handled by the rotor I1 is not only a very high voltage but 'is also a high frequency voltage. Great care should therefore'be taken to prevent flashing-over either between the brush II and ground, represented by shaft I8, or between one stationary contact I 9 and another. Flashing-over between the brush is and the shaft I3 is effectively prevented by means of concentric grooves I formed in the bottom of the rotor and the bottom of the distributor cavity I6. Theseconcentric grooves serve to greatly lengthen the surface paths along the respective insulating members. It should be observed that it is extremely important to prevent such flashovers with some materials such as Bakelite" which are rendered relatively conductive by such a flash-over so that subsequent flash-overs occur more and more readily, or a constant voltage leakage occurs.

The tendency toward flashing-over between stationary contacts I! is greatly increased by the rotating brush I8. In the first place, this brush may wipe some metallic particles from the stationary contact I! along the surface of the insulating housing ll. In the second place, if the sparking current continues as the brush ll leaves the contact I, it will naturally spark u rotor l1.

- aaoavu between them along the surface of the insulating housing H and transforms this housing into a relatively good conductor along the path of the spark. It should be noted that at the present time housings of material such as Bakelite which can be thus transformed are almost necessarily used because of the ease and accuracy with which such materials can be formed by molding. To prevent such flash-overs the pres.- ent invention contemplates a series of slots 53 formed in the wall of the cavity l6 between the stationary contacts. Since these slots are preferably quite narrow in order to facilitate" the passage of the brush thereacross, it is preferred i that at least two slots and preferably three be provided between each pair of stationary contacts i9. Such slots alone would help a great deal since, if a spark did occasionally pass across them, it would not transform the surface of the Bakelite within the, slot and, the slot would therefore maintain its insulating character. To increase the path that the current would have to follow along the walls of the slot, the deep ends of the slots preferably communicate with wells 54 which also serve a ventilating purpose, as is described below. It will be noted that the slots 53 are preferably slanting to facilitate the passage of the brush thereover. They will therefore communicate with one side of the wells 54 at their tops and with the other side of the wells 54 at their bottoms.

Considerable ozone is generated within the cavity i 6. If this ozone is allowed to accumulate it reaches a degree of concentration which has a very strong oxidizing effect. This may corrode the contacts i6 and I9 and it may also increase the danger of flash-overs. According to the present invention the ozone is prevented from becoming concentrated by ventilating the cavity l6. In the form. shown in Fig, 1 this ventilation is accomplished by providing passages 56 from some or all of the wells 5| outwardly and passages 51 opening into the cavity l6 at a position closer to the axis of rotation of the The rotating'rotor l1 acts as a centrifugal pump or blower for blowing air out through the slots 53 and the passages 56 and drawing air in through passages 51. To increase the blowing effect the periphery of the rotor is preferably provided with relatively deep slots 58.

Although this distributor is designed primarily to be able to handle the'currents and voltages of the circuit of Fig. 3, it may of course be used for the conventional ignition systems. end the bottom 26 of the ,coil housing will be supplanted by a simple terminal socket similar to the socket 33 for connecting the lead wire from the conventional coil directly to the contact 23. Inasmuch as it may sometimes be desirable to supply the distributors initially merely with the socket for the conventional ignition system and then to replace this socket with the housing shown in Fig. 1, having the booster unit therein, such socket may be threaded to the. cap 59 of the distributor so that it may be unscrewed and the housing 21 with its bottom 26 screwedin in its place.

This construction has another very important advantage of facilitating the replacement of a booster if the winding 3i should prove imperfect and fail. Thus, the coil HF and its

housing

26, 21 form a readily replaceable unit. This is particularly advantageous since the safeguards against flash-overs in cavity 16 leaves the wind- To this 7 3 ing li es the element most vulnerable to the high voltages carried.

The cap 59' may be secured to the body of the insulator housing il in any suitable manner as by the usual spring clips. Also, an annular recess 6i may be formed in one of these members with a corresponding 'ribin the other member with a gasket -therebetween for sealing around'the terminal socket '24.

Modified distributor and. coil combinations Figs. 5 and 6 illustrate a modified distributor and coil combination which isperhaps especially suitable for use in place of' conventional distributor heads. The rotor 62, it will be observed, is provided with fins 63 for ventilating purposes (any suitable vents 65 being provided) andwith an annular recess 64 for elongating the flashover path between the brush ity and the shaft it. The distributor head or cap'includes con

centric grooves

66 and 61 for preventingflashovers between' the stationary contacts and ground or radial contacts 68 respectively. It is also provided with radial slots 69 and wells 16 corresponding to slots 53 and wells 54 of Figs. 1 and 2 for preventing flash-over between the stationary contacts. Furthermore, it has been illustrated as including hollow chambers 12 for receiving

condensers

34 and 35 which wouldbe connected to ground by suitable leads not shown.

In this instance the secondary-winding 3i is sealed entirely within the distributor head or, more specifically, within the upward projection 16 thereon, being sealed therein-by a pressed and impregnated fibrous bottom wall 11. It will be noted that the primary winding 28 is located outside of the housing extension 16 and hence there is no danger of a flash-over between the winding 3| and the leads to the winding 28 and, furthermore, no problem is presented with respect to perfect sealing of the leads for winding 28 in order to protect the winding 3i. The leads for winding 3i are of course soldered into their respective terminal members so that they are effectively sealed. g

The primary winding 28 is carried by a cap 16 which telescopes over the projecting portion 16. The winding 28 is sealed and insulated with in the cap 19 by virtue of a plastic insulating compound 8i which is molded into place by a mandrel so that the cap 19 with the winding 26 therein will fit neatly over the projection 16. The leads 82 for the primary winding-28 may be soldered or otherwise sealed to terminal bushings 83 to which the condensers may be connected.

Referring to the arrangement of Fig. 8, the structure there shown employs a circuit arrangement similar to that of Fig. 3 but omitting the condenser 35 (although this condenser may be added if preferred). The high frequency booster transformer HF is made up as a unit with the distributor head in a one-piece housing 81'. The housing supports the high frequency coil or transformer and also serves as the distributor cap. The housing 61 is provided with a top portion 86 which extends through a constricted neck 89 to a cap 9|. In this embodiment of the invention the ordinary distributor cap may be entirely removed and housing 61 substituted therefor. The ordinary lead 92 to the center of the distributor head is simply inserted in an aperture in the top of the housing to engage one end of the secondary winding 3| (as is also true of Fig. 5). The other Vio end of the secondary winding is in electrical engagement with the distributor rotor 81.

Fig. 9 illustrates a construction similar to Fig. 8 except that the upper housing 88 is separable from the distributor cap 8 I and in fact may simply be plugged into the conventional cap 9i. Thus, to apply such a unit HF to an installation, the ordinary lead 92 to the center of the distributor head is removed. The terminal on one end of the housing 88, which is one terminal of the winding Si, is inserted into the distributor head and the removed terminal 92 then inserted in the top end of the housing 88 as seen in Fig. 8. The condenser ordinarily connected across the timer contacts II, or a special condenser employed if desired, is connected in series with the primary winding 28 of the high frequency unit HF to provide the high frequency oscillating circuit. Of course, if it is desired to employ an extra kick coil for added output, such a coil is then suitably connected in circuit with the primary winding 28 as is indicated below in connection with Fig. '7.

Fig. 10 illustrates another modification wherein I provide a high frequency ignition system employing a one-piece housing 96 for supporting the high frequency transformer or coil HF. In this instance the coil is of the Odin type. The housing 96 serves as a cap for the distributor as in Fig. 8, or the two parts may be separable as in Fig. 9. The upper portion 91, closed at the top, supports the coil HF and extends through a constricted neck portion to the cap portion. The coil HF as a whole includes a primary winding 98 and a secondary winding 99, the circuits being seen best in Fig. 11. A kick coil II is utilized in thiscircuit as a source of energy for charging the condenser I02. The kick coil IIlI under influence of the opening of the timer contacts I I raises the voltage from the battery H to a high enough value to be effective. The primary high frequency oscillating circuit, it will be observed, includes the primary winding 98, the condenser I02 and. the gap formed by the contacts II. The winding 98 induces a high voltage in the winding 99 which boosts the voltage produced by coil IIlI.

The ordinary ignition coil in use at the present time is mounted on the dash-board with an extended cable lead to the distributor. With this installation there is a considerable energy loss in the secondary which in turn impairs the operating efficiency of the ignition system. However,

' in my system with the high frequency coil HF mounted directly on the distributor in the onepiece housing the secondary loss is negligible. Furthermore, this assembly provides for a short lead to the condenser I02 with the resulting shortest possible primary oscillating circuit. In this arrangement the low frequency transformer or kick coil IIII may be mounted at any desired distance from the distributor.

Employing the small high frequency coil HF mounted on the distributor in a one-piece combination housing and distributor cap provides a very inexpensive and sturdy unit. This unit operating in the straight high frequency circuit described, provides in all a highly eflicient low cost ignition system.

Combination coil units In come instances it will be desirable to apply the system of my invention to an internal combustion engine having a conventional ignition system. In "these instances and perhaps in other instances it may be desirable to incorporate the high frequency unit in a single housing with the moans conventional low frequency coil. This has some advantage in economy and perhaps mayalso have some advantage in inducing a unidirectional or low frequency voltage in the high frequency secondary coil as well as in the low frequency secondary coil.

In any of the forms the HF unit may have either a non-metallic or a comminuted iron core, and the latter may be especially valuable if this core is alined with and close to the core III of the LF unit. One convenient form of construction to this end is illustrated in Fig. 4. The main body of the housing may be in the form of a jar I86 which may be upright or inverted and which may have a preferably square recess I" at its lower end for receiving the laminated iron core III of the low frequency coil. Around the core may first be wrapped the secondary winding 48 and thereafter the primary winding 42. A terminal III may be connected to both the primary and secondary windings, and a terminal I I2 connected to the other end of the primary winding. The other end of the secondary winding will be connected to the secondary coil ii of the high frequency unit HF.

The high frequency coil HF may be carried by a cap I II which closes the open end of the housing I86. This cap may desirably be provided with a depending sleeve I I4 for separating the secondary coil 3| from the primary winding 28 to prevent flash -overs between them. An inner cap I I8 may be telescoped over the high frequency unit HF so as to insulate it thoroughly from the low frequency unit. On the lower side of the inner cap H6 a recess corresponding to the recess Ill may be formed to receive the upper end of the core I08. The secondary winding 3| may be wound on a tube (or comminuted iron core) which may be supported by suitable formations on the inside of the inner cap H6 and on the main cap H3. The terminal cap III is preferably provided with an elongated boss I I8 which may have concentric grooves H9 formed thereon for elongating any surface flash-over path between output terminal I2I'and any other terminals or supporting members of the combination coil unit. It may also be noted that the provision of the inwardly extending sleeve H4 and the inner cap IIG makes any internal flash-over paths quite long.

A similar form of the combination coil unit is shown in Fig. 7 which includes additional elements and may be somewhat simplified with respect to the HF coil housing. In this instance the main housing I26 is made large enough to contain the low frequency coil LF including the primary winding 42 and the secondary winding 43 and large enough to house in addition a kick coil I 21 and

condensers

34 and 35. In this instance the battery 4| may be connected to a terminal I28 which in turn may be connected to primary winding 42 and to kick winding I21. The other ends of both of these coils are connected to a terminal I29 which will of course be connected to the timer contacts. The terminal I29 will also be connected to condenser which has another terminal I3I connected to ground, and to primary winding 28 of the high frequency unit HF, the other end of which is connected to condenser 34, which also has a terminal I3I connected to ground. The secondary winding 43 is connected at one end to theterminal I29 and at the other end to the secondary coil 8| of the high frequency unit. It will be understood of course 7 v 2,208,784 that the housing I23 may be filled with some insulating medium.

One advantage of the construction shown in. Fig. 7 is the relative ease with which the various parts may be replaced. Thus, it is seen that the high frequency unit HF and each of the

condensers

34 and 35 is supported by a housing member which is secured to a cap I32 by being threaded thereto. Hence, each of these units may be separately removed from the capv I32. As in Fig. l, the HF booster unit including a housing of molded insulation is readily re-' placeable.

In Figs. 12 to 14 another modified form of the combination coil unit has been illustrated, one which, on the whole, is somewhat preferred because of its ease of manufactureas well asits satisfactory operation. The housing in this unit includes a base I36, a support-partition I31, a

plain cylindrical sleeve body portion I39, and a.

cap I39. The base I36 is provided with deep concentric grooves I4! to prevent flash-overs, particularly between its output terminal. I42 and the supporting bracket which will normally be grounded and to which screws I43 may be secured. The support partition I31, which will be .of molded andpreferably fibrous insulating material, may be shaped as seen in Fig. 14 with an upper recess for receiving core I08 and a depending sleeve for receiving and insulating windings 28 and 3I. The partition I31 is also preferably provided with peripheral apertures I46 to permit the insulating composition with which the entire housing is eventually filled to pass through from the sleeve I38 intothe base I36. The cap I39 is preferably provided with a recess I4,'I to fit the upper end of the core I 08. It is also provided with three terminals I49 for making the connections necessary in addition to the output terminal I42. A resistance unit II may conveniently be connected between two of these terminals and a fourth terminal on can I39 and supported by them. Such a resistance is sometimes advantageous in the circuit of primary winding 42. It should also be mentioned that the connection between secondary windings 43 and 3| may be a bare, flexible, woven wire conpartacting core I08 as it passes through the tition or shelf I31.

Although winding 28, condenser 34 and contacts I I form a high frequency oscillating circuit,

- it is ,not vital that this circuit have any particular high frequency. The winding 29 and condenser 34 and alsothe condenser 35 may therefore have a wide variety of values. It may be mentioned, however, that some values which have been found satisfactory are:

Condenser 34---; microfarad .1 Winding 28 microhenry .413 Condenser 35 microfarad .3

The value of the latter shouldof course be so chosen as to produce the proper interruption of current in the low frequency primary winding 42 when used in conjunction with winding 28 and condenser 34. v

It is of course desirable that all of the housing members be formed of some suitable insulating material such as that known commercially as Bakelite whenever practical. It is obviously important that the various lead wires be thor- I oughly insulated from one another and from any Likewise, it is to be grounding conductors.

' understood that all of the coils will ordinarily be completely sealed and insulated from one another by pouringa molten insulating compound into the housings. .Such a compound will, upon solidifying; hold the various parts in proper positions.

From the foregoing it is seen that a variety of forms of apparatus have been devised for handling the high frequency and high voltage generated by m'yignition system or any other system for which such special apparatusmay be suitable.

The" disclosures of this application are illustrative and the invention is not to be limited by them. In fact, if modifications or improvements are not at once-obvious, they may be devised in the course of time to make additional use of the broad ideas taught and covered by this application. The claims are intended to point out novel features and not to limit the invention except as may be required by prior art.

' I claim:

1 The combination of a low frequency ignition coil and .a high frequency booster whereby very high'voltages are produced having high frequency characteristics, and a distributor including a rotor and a housing therefor having a series of contacts adapted to be connected by the rotor to the coil and booster, said rotor having periph eral formations for increasing the circulation of air thereby and said housing having vents whereby the rotor will cause air to circulate through said housing to prevent the concentration of ozone therein.

2. The combination of a low frequency ignition coil and a highfrequency booster whereby very high voltages are produced having high frequency characteristic, and a'distributor including a rotor and a housing therefor having a series of contacts adapted to be connected by the rotor to the coil and booster,' said rotor having peripheral formationsfor increasing the circulation of air thereby andsaid housing having vents whereby the rotor will cause air to circulate through said housing to prevent the concentration of ozone therein,

said distributor also having grooves formed beconnected with the ignition spark means for causing sparks in them.

4; The combination of ignition spark means, a

distributor and a high frequency booster unit- .including a housing having a distributor cavity therein, a rotor positioned in said cavity, a high frequency secondary winding sealed within the housing and connected to the rotor, at high frequency primary winding in inductive relationship to the secondary winding, a plurality of contacts within the distributor cavity adapted to be connected with the ignition spark means for causing sparks in them, vents extending from the peripheral portion of the cavityoutwardly, and air inlets opening at a more central portion of the cavity.

5. The combination of ignition spark means, a distributor and a high frequency booster unit including a housing having a distributor cavity therein, a rotor positioned in said cavity, a high frequency secondary winding sealed within the housing and connected to the rotor, a high frequency primary winding in inductive relationship to the secondary winding, a pluralityof contacts within the distributor cavity adapted to be connected with the ignition spark means for causing sparks in them, vents extending from the peripheral portion of the cavity outwardly, and air inlets opening at a more central portion of the cavity, said rotor having peripheral projections thereon for acting as a centrifugal blower.

6. A distributor for distributing current to a plurality of ignition spark means, including a housing having a distributor cavity therein, a rotor positioned in the cavity, a plurality of contacts within the distributor cavity adapted to be connected with the ignition spark means, vents extending from the peripheral portion of the cavity outwardly, and air inlets opening at a more central portion of the cavity, said rotor being substantially circular in form and having a plurality of alternate projecting peripheral portions and depressed peripheral portions thereon for acting as a centrifugal blower.

7. The combination of a distributor and a high frequency booster unit including a housing having a distributor cavity therein, a rotor and contacts positioned Within said cavity, an extension carried by the housing and having a recess therein, completely sealed from the cavity and from the outside atmosphere, a high frequency secondary Winding within the extension and connected to the rotor, and a high frequency primary winding in inductive relationship with the secondary winding.

8. The combination of a distributor and a high frequency booster unit including a housing having a distributor cavity therein, a rotor and contacts positioned within said cavity, an extension carried by the housing and having a recess therein. completely sealed from the cavity and from the outside atmosphere, a high frequency secondary winding within the extension and connected to the rotor. and a high frequency primary winding in inductive relationship with the secondary winding, and sealed within a removable cap telescoping over said extension.

9. The combination of a distributor and a high frequency booster unit including a housing having a distributor cavity therein, a rotor and contacts positioned within said cavity, an extension carried by the housing and having a recess therein completely sealed from the cavity and from the outside atmosphere, a high frequency secondary winding within the extension and connected to the rotor, and a high frequency primary winding in inductive relationship with the secondary winding, said extension being readily removable from the housing whereby it may be readily interchangeable with other extensions.

10. The combination of a housing having a main body portion having an aperture therein, ignition apparatus within the main body portion, and a replaceable unit including a separate casing molded of insulating material and separably supported by the main body portion as a closure for the aperture thereof, and a high frequency transformer including a secondary winding sealed within the casing and connected with said apparatus, and a primary winding in inductive relation therewith.

11. The combination of a low frequency ignition coil and a high frequency booster including a casing having a main body portion, a low frequency ignition coil within the main body portion, an end portion closing 05 one end of the body portion, and a high frequency boosting unit sealed within the end portion and including primary and secondary windings, said end portion having an output terminal for the secondary winding separated from all external conducting parts by a projection of insulation, said projection being concentrically grooved to increase the length of flash-over path along the surface thereof from said terminal to any other conductor.

12. The combination of a low frequency ignition coil and a high frequency booster including a casing having a main body portion, a low frequency ignition coil within the main body portion, an end portion closing off one end of the body portion, and a high frequency boosting unit sealed within the end portion and including primary and secondary windings, said end portion having an output terminal for the secondary winding separated from all external conducting parts by a projection of insulation, said projection being concentrically grooved to increase the length of flash-over path along the surface thereof from said terminal to any other conductor, said low frequency coil including an iron core and said high frequency secondary winding being inductively positioned with respect thereto.

13. The combination of a low frequency ignition coil and a high frequency booster including a casing having a main body portion, a low frequency ignition coil within the main body portion, an end portion closing off one end of the body portion, a high frequency boosting unit sealed within the end portion and including primary and secondary windings, said end portion having an output terminal for the secondary winding separated from all external conducting parts by a projection of insulation, said projection being concentrically grooved to increase the length of flash-over path along the surface thereof from said terminal to any other conductor, and an insulating partition between said end portion and said body portion supporting said low frequency coil thereon and said high frequency booster thereunder.

14. The combination of a low frequency ignition coil and a high frequency booster including a casing having a main body portion, a low frequency ignition coil within the main body portion, an end portion closing off one end of the body portion, a high frequency boosting unit sealed within the end portion and including primary and secondary windings, said end portion having an output terminal for the secondary winding separated from all external conducting parts by a projection of insulation, said projection being concentrically grooved to increase the length of flash-over path along the surface thereof from said terminal to any other conductor, and an insulating partition between said end portion and said body portion supporting said low frequency coil thereon and said high frequency booster thereunder, said partition having passages formed therethrough to facilitate the filling of said body portion and said end portion with an insulating and sealing fluid.

15. As an accessory for amplifying the output of ignition systems having the usual spark coil, distributor head, timer contacts and condenser across the contacts, a high frequency oscillation coil unit having a supporting terminal end for insertion in the top of the distributor head for connecting one end of a secondary winding of the coil with the distributor arm and a second terminal for connection with a terminal or, a secondary winding of the spark coil, and a pair of leads on the unit for the primary winding for connection to the condenser and the timer contacts for providing the primary oscillating circuit for the high frequency coil.

16. In an ignition system having the usual distributor with timer contacts, rotor, and condenser across the contacts, a low frequency source of energy, a high frequency oscillating coil having a primary for connection with said low frequency source and said condenser and timer contacts, and a secondary for connection with the low frequency source and distributor rotor, and a combination coil housing and distributor cap fitting on said distributor for supporting said high frequency coil and covering said distributor and distributor rotor as the cap' therefor.

17. In a distributor cap for the usual distributor for an ignition system, a hood-shaped lower portion and an integral top portion having a cavity therein for carrying an ignition coil having two high frequency windings and means in the cap for completing an electrical circuit from one winding of said coil to the rotor in the distributor, and means for completing a closed circuit from the other winding through the timer contacts in the distributor and a condenser.

18. An ignition unit including in combination a housing, a low-frequency coil unit within the housing at one end thereof, a high-frequency coil unit within said housing at the other endthereof including a secondary winding, an output terminal onthe housing for the secondary winding and available on the outside of. said housing at said other end separated from all external conducting parts of said ignition unit by an insulating portion concentrically grooved to increase the length of flash-over path along the surface thereof from said terminal to any other conductor, a primary winding in said housing at said other end surrounding said primary winding and supported in inductive relation thereto, and an insulating partition in said housing between the low-frequency coil unit and the high-frequency coil unit with said partition supporting either one coil unit or the other when the housing is standing in an upright position, with said partition being of such a configuration and acting in such a manner as to maintain the supported coil unit in a relatively fixed position in said housing.

19. The combination in ignition apparatus of a distributor and a high-frequency coil unit including housing means with one portion of said housing means having a distributor cavity therein, a rotor and contacts positioned within said cavity, a second portion for said housing means separable from said first portion but fixedly connectible therewith, said second portion having a recess therein, a high-frequency primary winding Within said recess and in inductive relationship with the secondary winding, said primary winding having at least one end thereof adapted for connection to a condenser in the ignition apparatus to provide a primary oscillating circuit for the high-frequency coil unit..

HARRY B. HOL'I'HOUSE.