US2257781A - Distributor - Google Patents

Description

J. BOHLI DISTRIBUTOR Oct. 7, 1941.

Filed Oct. 27, 1958 INVENTOR.

MW ATTEY.

Patented Oct. 7, 1941 UNITED STATES PATENT OFFICE DISTRIBUTOR sppuesun october zr, 193s, sensi No. 231,220

(ci. zoo-24) iClaims.

This invention relates to electrical apparatus and more particularly to ignition distributors adapted for use in internal combustion engines.

In high tension ignition distributors heretofore provided considerable diiliculty has been encountered in `preventing dash-,overs from one contact to another within the distributors thereby causing pre-ignition in the engine cylinders with which the aected circuits are associated. This is particularly true in distributors used in modern, multi-cylinder engin'es wherein the contacts lmust be comparatively closely spaced, in order to keep the size and, weight of the distributor within reasonable limits. The above difilculty is enhanced in distributors used on aircraft engines since the rareiled air and the low atmospheric pressure in which aircraft fly.

greatly facilitate and increase the probability of dash-overs. Although various methods have been developed to insure dependable operation of ignition distributors, especially during high altitude flying,V these efforts have resulted in structures having prohibitive dimensions and weights for aircraft use. 1

It is accordingly one of the objects of the present invention' to provide a novel ignitiony distributor wherein the foregoing difficulties and disadvantages are obviated.

Another object of the invention is to provide a novel ignition distributor for use on internal combustion engines which is so constructed that the electrical contacts therein are maintained in a liquid dielectric bath at all times during operation irrespective of the Vposition of the distributor.

Still another object is to provide a device of the above character wherein a liquid dielectric is maintained under pressure around the electrodes during operation of the device.

A further object is to provide an oil insulated distributor for internal combustion engines which is so constructed that foaming of the oil and the creation of air bubbles therein about the immersed contacts is substantially eliminated.

A still further object is to provide a novel ignition distributor which is smallenand more A is simply constructed and yet durable and eilicient in operationat all altitudes and in all positions of operation.

. 'I'he above and further objects and novel fea--v tures of the invention will more fully appear from the following detailed description when the same is. read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing is for the purpose of illustration only and is not intended as a definition of the limits of the invention, reference being primarily had for this latter purpose to the appended claims.

In the drawing wherein like reference characters refer to like parts throughout the several views,

Fig. 1 is an elevation view, partly in section and with parts broken away, of one form of the novel apparatus ccmprehended by the present invention; and,

Fig. 2 is a sectional view taken substantially I on line 2--2 of Fig. 1, showing the rotatable contact carrying element in plan view.

A single embodiment of the present invention is illustrated in the drawing, by way of example, in the form of a radio shielded distributor comprising a light metallic cup-shaped housing l and a metallic cover 8 therefor. Said cover is preferably piloted in housing .member l by an annular portion l and is secured in place by a plurality of screws l which threadedly engage tapped recesses in the upper edge of said housing.

The distributor proper is removably fitted within metallic housing I, 8 and, in the illustrated embodiment, includes a cuplike lower portion 9 made of any suitable insulating material and a cap on upper portion II made of similar material. An annular gasket II is preferably provided between the engaging surfaces of parts 9 and il. Cap 9 is provided with a shoulder i2 adapted to be engaged by 'portions 1 of cover 8, whereby above-described parts vmay be rmly held in assembled relation by screws I.

Insulating member 9 has an internal shoulder or ledge i3 in which are embedded a plurality of equally spaced, circularly-disposed contacts i4 which are electrically connected to each other by any suitable means and connected by an insulated cable iI-to a suitable source or high tension current, such as a magneto (not shown). The exposed ends of contacts It are flush with the surface of shoulder Il and are surrounded by recesses il in said surface. Cable I! extends through registering openings in housing B and insulating cup and is electrically connected to one of the contacts il by a small coil spring Il or other suitable means.

Distributor cap lil is provided with a plurality' of circularly arranged axially extending contacts II each of which is remouably mounted in said cap directly opposite one of the high tension contacts it and is connected by an insulated cable iii to an ignition device, such as a spark plug (not shown) in the cylinder of an engine with which the distributor is associated. The inner ends of contacts iii, which may be made oi copper or othersuitable material are surrounded by annular recesses 22d and have the faces thereoi1v iiush with the inner surface of cap ill. Cables iS extend through registering openings in cover d and cap i@ and are electrically connected to contacts iii by means oi A' coil springs 2i. In order to shield the ignition system and thus prevent radioA interference thereby, each of the cables i5 and i3 is preferably surrounded by a flexible metallic tube 22, the inner end of which has a metallic spool 23 secured thereto. The inner flanged ends of spools 2S are held in engagement with distributor parts il, i@ and in assembled relation by suitable gland nuts @il that threadedly engage the openings in housing l through which the cables extend. The two insulating elements il and I0 which support stationary contacts Iii and I8 dene an enclosedspace in which a novel rotatable distributor element 25 operates. As shown, said element is in the form of a wheel which is keyed at-its hub 26 to the inner conical end of a shaft 21 that is rotatablyv .iournalled in a bearing 2B which has a tight t in aligned tubular bosses 29 and 36 which extend interiorly and exteriorly of and integral `with-ccup 9 and housing 5, respectively. Element 25 may be held against axial movement on shaft 21 by a screw 3i and the shaft may be rotatably driven in any well-known manner by some suitable part of the engine to which the distributor is attached. The periphery or rim portion 32 of rotatable element 25 is connected by a thin disc to hub iii and has an axially exten ing therethrough in line with the stationary contacts iii 'and I8. Slidably mounted in said'opening are a pair of contact members 334i, iii which are adapted to be yieldingly pressed against said sets of stationary contacts by any suitable means, such as a spring 3E interposed therebetweenaid spring also serves as an electrical conductor to successively complete the electwo sets of trical circuit between the various pairs 0f OPPQfN'Qri sitely disposed contacts I4 and I8 during'th rotation of element 25 with shaft 21.

For a purpose to more fully appear hereafter, rim 32 has bored therein a plurality of openings 31 which extend in a radial direction between the inner and outer peripheral faces thereof and a plurality of radial extending grooves 38 are cut in the upper and lower faces thereof, as viewed in the drawing. Connecting disc portion 33 is also provided with a plurality of axially extending openings or perforations 39 to permit the passage of a liquid dielectric to be hereinafter discussed.

The space between members 9 and I0 is preferably subdivided into three compartments by a pair of perforated plates M and 4I which surround and engage hub 2G and boss 29, respectively. The center chamber [32 in which distributor rotor 25 operates is connected to annular chamber 'by perforations iid in plate `40 and to upper chamber l5 by perforations 48 in plate 40.

For the purpose of providing insulating means between the spaced contacts to prevent Ilash-- overs or sparking therebetween, a quantity of liquid dielectric 41, such as oil for example, is

provided in the chambers referred to above, said asomar liquid being introduced into said chambers through central openings in cover 6 and cap I0 which openings are normally plugged by threaded screws t3 and 49, respectively. As shown, said screws are provided with small Ventilating holes which connect the interior of chamber d5 with i the atmosphere. The quantity of liquid dielectric employed may vary between quite wide limits, but preferably the quantity should be such that cil sealing means Sd will not be covered by 1 the liquid, irrespective of the position of the clistributor. As will be more fully pointed outhereinafter, liquid d1 will be forced during the rotation of rotor 25 through passages 31 and maintained under pressure due to centrifugal force in the clearance space between rim 32 and the adjacent surfaces of insulating members 9 and ill.

in the operation of the embodiment above described, distributor rotor 25 together with contacts or brushes 3d and 35 are rotated in synchronism with the crankshaft, for example, of an internal combustion engine to thereby periodically and successively complete circuits between a source of high tension current connected to input brush or contacts I4 and a plurality of ignition devices connected to contacts or brushes I 8 in a manner and for a purpose well-known and understood in the art. Rotor 25, when rota.- tably driven by shaft 21 constitutes in eect a centrifugal pump whchis effective to force liquid 41 outwardly through passages 31 into the clearance space between rim 32 and the adjacent walls of members 9 and I0. Thus, duringoperaticn of the distributor the liquid dielectric is maintained under pressure in said clearance space and in recesses I6 and 20 surrounding the points of contacts I4 and I8, thereby preventing the formation of air bubbles on or around said contacts and providing an insulator to obviate flash-overs pawn 33 40 between the various contacts. Grooves 38 may ding oenbeprovide both sides of the rotor to insure positive circulation he oil or other liquid dielectric and thus obviate theforrnation of any air bubbles behind or in front `f"the * momma brushes 34 and 35. Openings 39 in the disc portion of rotor 25 are provided to insure the equalization of oil pressure on both sides of the rotor during operation thereof.

If the liquid Vin excess of that which is necesry to completely immerse the contacts and insulate the same from one another during rotation l of rotor 25, i. e., the reserve liquid, were permitted to rotate with the rotor the same would become mixed with air and foaming would result. This would in turn materially reduce the eiiciency of the liquid as a dielectricl or insulator. Accordingly, the reserve supply of oil in the distributor of the present invention is permitted to circulate through reservoir chambers 43 and 45. The perforations in separator plates 40 and 4I are comparatively small in order to permit only a small amount of oil to circulate thereby preventing the mixture of any liquid with air.

By maintaining the oil or other liquid dielectric around all of the distributor contacts under pressure, during the operation of the distributor, and free of air bubbles, the possibility of flashovers or sparks between spaced contacts immersed therein is substantially'eliminated. It may also be noted that the supply of oil under pressure in recesses I6 and 20 prevents any burning of the insulation 9 and I0 in which contacts I4 and I8 are mounted by sparkswhich might occur upon engagement and disengagement of said contacts by rotating brushes 34 and 35.

There is thus provided a novel ignition distributor for internal combustion engines which is small and compact, yet efficient and dependable in operation at all altitudes and in all positions. The contact points of the novel distributor hereby provided may be immersed at all times and in all positions during operation in a liquid dielectric which is maintaned under pressure and free of air bubbles by the operation of the distributor I tributors of equal capacity heretofore provided.-

Although only a single embodiment of the invention has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto, as will now be apparent to those skilled in the art. Various changes may be readily made, such' as in the size, composition, design and arrangement of parts illustrated without departing from the spirit and scope of the invention. For a definition of the limits of the invention reference is had primarily to the appended claims.

What is claimed is:

1. A high tension distributor comprising insulating means forming a fluid chamber, a liquid dielectric in said chamber, an input brush,'a plurality of output brushes, rotatable means in said chamber for maintaining said liquid under' pressure around said brushes, said rotatable necting said input brush successively with said output brushes.

2. In a distributor for internal combustion engines an annularly extending input brush, a plurality of circularly arranged output brushes, a rotatable insulator interposed between said input and output brushes, means carried by said insulator for successively electrically connecting said output brushes with said input brush, and a liquid dielectric in the space between said brushes and said insulator, said rotatable insulator having a plurality of radially directed passages therein for the circulation of said liquid.

3. In apparatus of the class described, a housing having a circular chamber therein, an annularly extending conductor in said housing adjacent the periphery of said chamber, a pluralityof .'circularly arranged contacts in said housing adjacent the periphery of said chamber, a disc-like dielectric rotor having an enlarged peripheral portion interposed between said conductor and contacts, said enlarged peripheral portion having a plurality of passages extending in a radial direction therethrough, means carried by said rotor for successively electrically connecting said contacts and said conductor, and a quantity of liquid dielectric partially filling said chamber.

4. In apparatus of the class described, a housing having a chamber therein, an elongated conductor in said housing adjacent the periphery of said chamber, a plurality of contacts in said housmeans having a plurality of passages therein connecting the central portion of said chamber and the peripheral portion thereof and means carried by said rotatable means for electrically coning adjacent the periphery of said chamber, a dielectric rotor having a portion thereof interposed between said conductor and contacts, means carried by said rotor for successively electrically connecting said contacts and saidy conductor, and a quantity of liquid dielectric partially lling said chamber, said rotor having passages therein for conducting said liquid from the central portion of said chamber to the periphery thereof during rotation of the rotor.

JAKOB BOI-111.

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