Sept. 19, 1 939. M. E. PETERS ET AL INTERNAL COMBUSTION ENGINE IGNITION Filed sept. 22, 1936 2 sheets-sheet 1 FIG,2
IIIIII A ATTORNEY.
Sept. 19, 1939. M. F. PETERS ET AL INTERNALCOMBUSTION ENGINE IGNITION 2 sheets-sheet 2 Filed Sept 22 INVENTOR. fz-mu f ,0f/'fwe #mw 510,15
ATTORNEY.
Patented Sept. 19, 1939 `PMENT oFFlcE INTERNAL COMBUSTION ENGINE IGNITION Peters, Beltsville, Md., and R. Harry Melville F.
Stone, Bound Brook,
flex Metal Hose Co., a corporation of New Jer- N. J., assignors to Tite- Application September 22, 1936, Serial No. 102,020 16 Claims. (Cl. 1.'?,Ii148)` l This invention has special reference to the insulation, radio shielding and protection of the ignition conductors of internal combustion engines, but is capable, especially as to some of its features, of a large number of widely different applications.
One objectvof the invention is to provide im-` proved radio shielded and insulated ignition conductors for an internal combustion engine.
A further object of the invention is to provide an electric conduit with a conductor therein, and spaced therefrom by solid. segmental, insulating means.
A further object of the invention is to provide a conduit and a conductor therein having a plastic insulating and dielectric compound within the conduit and about the conductor.
A further object of the invention is to provide a flexible conduit having a conductor therein with solid, segmental, insulating means spacing the conductor from the conduit and a plastic insulating and dielectric compound within said conduit and about said conductor and insulating means. l
A further object of the invention is to provide an improved new and useful composition of'matter. v
A further object of the invention is to provide a plastic insulating and dielectric compound.
Otherand ancillary objects of the invention will appear hereinafter.
In the accompanying the invention;
Fig. l is a side elevation of an ignition manifold; v
Fig. 2 is a section on the line 2-2 of Fig. l on an enlarged scale;
Fig. 3 is a section on theline 3--3 of Fig. l to the same scale as Fig. 2;
Fig. 4 is a section, with the parts partly broken away, on theline 4--4 of Fig. 1 on an enlarged scale;
Fig. 5 is a section, with the parts partly broken away, on theline 5--5 of Fig. 1 on the same scale as Fig. 4;
Fig. 6 is a section, with the parts partly broken away, on the line 6-6 of Fig. 1 on the same scale as Fig. 4; v
Fig. 7 is a fragmentary view of an end of the manifold broken away to show in section the construction thereof;
Fig. 8 is a sectional view, on the same scale as Fig. 7, of the end to which the ignition leadis secured, of a tube extending from the end of the manifold.
drawings which illustrate Fig. 9 is a view, partly broken away and partly in section, to the same scale as Figs. '7 and 8, of a spark plug lead;
Fig. 10 is a fragmentary ing a modiiied form of segmental insulating and supporting means for the conductor in the conduit and Figs. 11, 12, and 13 are cross sectional views of the manifold showing modied forms of the-solid insulating support for the conductors.
Referring to Figs. 1 to 9 of the drawings, the apparatus there shown is intended for use with an ignition system for internal combustion engines wherein leads extend from the spark plugs to a so-called manifold whereby the ignition conductors are guided about the shaft of the engine and conductors lead from the manifold to a magneto whereby the electricity for the ignition is conducted from the magneto to the various spark plugs through timing and distributing devices as are well understood in connection with internal combustion engine ignition.
The leads are further provided with metal covering which operates as a shield to prevent interference by the ignition current with radio apparatus in the neighborhood especially when the engine and radio apparatus are mounted in such close proximity as is necessary with the limited space available in an aeroplane.
In the structure of Figs. l to 9, inclusive, the manifold comprises a metal casing I, having theinlet 2 for the conductors from the magneto andoutlets 3, 4, 5, 6 and 1 for the conductors leading to the spark` plugs. At other points than the inletand outlets the manifold casing is rectangular with rounded corners as shown in Figs. 2 and l1 to 13, or it may be round or polygonal or of other suitable shape, the inlets andoutlets referred to being offset as clearly appears from Figs. 3, 4, 5, and 6.
Theconductors 8 from the magneto (see Fig. 6) are individually insulated each being covered with the insulation 9, or the conductors might be mounted and insulated as hereinafter described in connection with the manifold or they might have segmental insulators or beads threaded on them and the spaces filled with a plastic insulating compound as hereinafter referred to. These insulated conductors are included within a metal conduit i0 connecting with the radio shield or metal casing about the magneto and having an end secured in the metal plate il secured to the metal casing l2 of theinlet 2 `by means of a screw collar I3.
Theconductors 8 extend within the inlet and Bossu-i5 APR 22 i941 section of a lead havoil and 1/3 mica, the rubber where added displacing a proportionate amount of the polymerized oil.
The rubber may be ground and mixed with the castor oil and insulating material, such as mica, etc., and then the mixture heated until the oil polymerizes. The ground rubber may also be mixed with the castor oil after the last has been polymerized and the mixture then heated. Also the rubber may be liquefied or dissolved in the hot polymerized oil and the mixturethen mixed, While hot, with the comminuted mica.
In making use of the plastic compound in connection with the ignition conductors, casings, and conduits, as above referred to, the manifold is provided with aninlet nipple 3| having a check valve preventing the exit of the compound after it has been forced in, to which may be applied an instrument similar to an air pump or grease gun for forcing in the compound. The plastic insulating and dielectric composition as referred to may thus be forced into the manifold spaces aboutl the conductors and supports, also passing through the openings from the manifold. into the spark plug leads, whereby the spaces in such leads about the conductors and insulating beads thereon will be filled with the composition.
The Wedges or strips I5 are divided into longitudinally distributed sections with clearances between the sections so that the compound can readily percolate to all spaces within the manifold.
To facilitate the filling of the ignition leads with the compound, openings 32 and 33 (see Fig. 9) of the leads will be provided in the couplings at the ends of the leads, through which the compound may be forced in at each end of the lead.
The opening 32 is controlled by aring 34, rotatable upon the coupling and having a hold adapted to be moved into and out of registry with the hole 32. When in such registry communication is afforded with the interior by which the compound may be forced into the lead by any suitable means, and after such operation has been completed the opening may be closed by rotating the ring 3l until the hole in it is out of registry with the hole 32 in the coupling, and thus communication with the exterior is shut off.
Similarly, the opening 33 is controlled by alrotatable ring 35 having ahold 38 adapted to be moved into and out of registry with the hole 33v as the ring is rotated. 1
In applying the plastic composition to the apparatus described, the apparatus is first thoroughly dried, theopenings 32 and 33 in each of the leads being open, so as to remove all traces of moisture, the apparatus being heated to about F. The. apparatus is then placed in a vacuum tank or container with` the vent openings in the leads still open, which will operate to exhaust all air from the interior of the manifold and conduits so that the plastic composition when forced in under pressure will enter all spaces therein and the formation of bubbles will be avoided. While in this condition the composiu tion is forced under pressure into the manifold and spark plug lead conduits, entirely and completely filling the same and a solid, compact mass is secured throughout.
In order to avoid possible corrosive action of the compound on theconduits containing it,v
they should be constructed so as to present noncorrosive surfaces to the compound. This may be accomplished by tinning their interiors, that is coating them witlrtin or in other suitable ways. In the case oi' the strip formedtube 24, the tube might be formed from a tin or other suitably plated strip.
It will be observed that the conductors are entirely enclosed in metal, radio shielding casings or conduits whereby interference with neighboring radio apparatus by the ignition cur rents in the conductors is avoided.
In Fig. 10 is shown a modified construction wherein the.beads 31 consist of cylinders telescoping with each other to a greater or lesser extent7 and with suitable clearances to permit flexing, instead of the form ofbeads 30 as previously referred to.
In Fig. 1`1.is shown a modified form of insulating support for the conductors within the mani fold. In this structure as illustrated in Fig. il, the molded insulating support of Bakelite or other suitable insulating material, within the metal casing l' of the manifold consists of thecentral section 38, having grooves within which theconductors 8 are located and having its pointed ends bearing against the manifold casing i. At the sides of thesection 38 are thesections 39 and 40, which are similar to each other and have projections entering the grooves in thesection 33 and hold the conductors in place, thesections 39 and I0 respectively having the projections il and 42 bearing against the casing i so that the conductors are securely' insulated and firmly held in position.
In the modification shown in Fig. l2, the moldedbakelite support 4,3 for theconductors 3"' within the manifold metal casing i", as will be seen from the figure, comprises a central portion having its ends bearingagainst the casing i" andlateral projections 44 bearing against the casing, the whole being arranged to provide grooves within which theconductors 8 are located.
In the modification shown in Fig. 13, the construction is similar to that of Fig. 12 except that the central portion I5 of the bakelite support for the conductors' is broader and the lateral pro jections 46 are shorter, but otherwise the structure is similar to that shown in Fig. 12.
While the invention has been illustrated in what are considered its best applications, it may have other embodiments without departing from its spirit, and is not, therefore, limited to the structure shown in the drawings.
What we claim is:
1. In a radio-shielded ignition system, the combination with a radio-shielding manifold of radio-shielding spark plug leads extending therefrom. conductors in said manifold and leads, said manifold being arc-shaped. and a relatively rigid arc-shaped insulating support for the conductors within the manifold, the longitudinal axis of'said support being curvedY in substantial accordance with the longitudinal curvature of said manifold.
2. In a radio-shielded ignition system, the combination Iwith a radio-shielding manifold of radioshielding spark plug leads extending therefrom, conductors in said manifold andleads, said manifold ybeing arc-shaped, and a relatively rigid arc-shaped insulating support for the conductors within the manifold, the longitudinal axis of said support being curved and substantially conforming to the longitudinal curvature of said manifold and a plastic insulating and dielectric compound radio-shlelding spark plug leads extending there- 75