US1548667A - Timer for explosive engines - Google Patents

Description

Aug. 4, 1925.

' v52 CJEZK JOSIPH J. 0055s.

J J DOBES TIMER FOR EXPLOSIVE ENGINES Filed June l0, 1919 Patented Aug. 4, 1925.

UNITED STATES PATENT OFFICE.

:rosnrn J. DOIBES, or CHICAGO, ILLINOIS, AssIGNoR TO THE nnnnson COMPANY, A CORPORATION or INDIANA.

TIMER FOR EXPLOSIVE ENGINES.

To all whom it may concern:

Be it known that I, JOSEPH J. Doers, a citizen of the United States, and'resident of Chicago,'in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Timers for EX- plosive Engines; and I do hereby declare that the following description of my invention, taken in connection with the accompanying sheet of drawings, forms a full, clear, and exact specification, which will enable others skilled in the art to which the said invention appertains to make and use the same.

This invention has general reference to timers for explosive engines; and it consists, essentially, in the novel and peculiar combination of parts and details of construction, as hereinafter first fully set forth and described, and then pointed out in the claims.

The object of this invention is the production of an eiiicient, serviceable, and comparatively inexpensive timer for regulating the time of explosion of the charges in explosive engines, so that the explosion or ignition of the charges will occur at the proper moment. It is a wellknown fact that in order to effect the ignition of the explosive charges in internal combustion engines at the correct moment, this ignition must take place shortly before the moment when the pistons of the engines reach the limit of their compression strokes, and that a minute fraction of time is required to ignite these charges before they become efiective. It is, furthermore known that the speed of the engine necessitates regulation 'of the time when ignition must take place, and that the faster the engine is working, the earlier the ignition of the charge must take place.

I11 internal combustion engines of the present day, the ignition of the explosive charge is eifected'by an electric spark which is derived from electric storage batteries, and magnetos, and the proper time when the ignition takes place is regulated by what is technically known as a timer, which at the proper moment sends an electric current through an induction coil to the spark plug where an electric spark is formed in the spark gap of the latter device.

It is to this class of instruments to which my present invention appertains, and in the drawings forming a part of this specification, I have shown an embodiment of my present invention.

In these drawings Figure l is a front elevation of this timing instrument. Fig. 2 is'a sectional view on the indirect line 22 of Fig. 1. Fig. 3 is a detached sectional view of the rotor and a portion of its driving shaft taken on the line 33 of Figure 1. Fig. 4 is a sectional view on line 44 of Fig. ,1. Fig. 5 is a perspective view of one of the contact electrodes detached.

Like parts are designated by the same characters and symbols of reference in all the figures.

The reference numeral 10 in the drawings designates the casing of this timer. It is, preferably, a cup-shaped steel stamping of circular contour having a straight rim 12, and a dome-shaped or conical end 13.

This casing is attached or held to the gear casing or crank casing of an internal combustion engine, in any approved manner, preferably by a resilient bar 14, Fig. 2, pressing upon the casing at the apex of the cone. Into the open end of this casing projec ts the cam shaft 15, which extends from the crank casing and is connected to the crank shaft by gearing, not shown, but of well-known construction. Upon the outer end of this shaft 15 there is mounted a rotor, consisting of a hub 16, said hub having an extension 17, to which there is pivotally connected an electrode 18, by a pin 19, passing through lugs 20, formed on the contact electrode 18, and through the extension 17. This electrode is a curved, preferably hardened steel blade which has at one end a curved tail or projection 21, Fig. 1, which bears againstthe extension 17. In this protuberance there is a bore 22, and in this bore there is a light coil spring 23, which bears against the under side of the curved electrode 18, and forces the tail'21 against the extension 17 and thereby preknown Ford automobiles, is, nevertheless adapted for employment on other explosiveengines; and while, as shown, it is adapted for use on four-cylinder engines, it is capable of being installed in motors having a greater or lesser number of cylinders, as will hereinafter appear.

The rim of the casing 10 is punctured by four screw-holes placed 90 degrees apart, thus dividing the easing into four equal portions. In these screw holes there are placed, preferably, machine screws 25, having their heads within the casing. To each of these screws 25 there is connected an electrode, which consists of a hardened steel blade shaped to arcuate form, as at 26, and then by a close return bend 27 to a straight portion 28, which has a slotted aperture 29, by which it is passed over the screw 25.

Between the straight portion 28 and the inner surface of the casing wall, there is placed a washer 30; and between the outer surface of the casing and the nut 31 on the screw 25, there is another washer 32, all of which washers are, preferably, made of a slightly elastic material which is not a con ductor of electricity, to insulate the electrodes from the timer casing.

To the screws 25 there are connected the usual electric conductors 33, that connect the electrodes, by way of the induction coil, to the spark plugs of the motor.

Attention is now invited to the electrodes, the curved portions 26 of which are spaced a certain distance from the center of the shaft 15, and the electrode 18, the curved member of which is spaced from the center of the shaft a distance slightly in excess of that of the electrodes 26 when the electrode 18 is in outwardly extended position. It follows that when the rotor revolves and the electrode 18 thereof approaches an electrode 26, the electrode 18 will be slightly depressed and its coil spring compressed, so that the two electrodes 18 and 26 will be in positive netallic contact and slide upon each other, and that by the electrode 18 sweeping over the electrode 26, both electrodes will be at all times kept perfectly clean and free from any deposit of dirt, and other foreign matter that might reach and gather in the interior of the casing 10.

It will be seen that the slight resiliency of the insulating washers 30 and 32 and also any slight resilency in the me tallic members 26 will tend to the production of a sharp break in the current as the movable electrode leaves any one of the fixed electrodes, thereby preventing arcing-and producing a hotter spark at the plug, due to a well known principle of the induction coil.

I have hereinbefore mentioned that the electrodes have the slotted portions 28. This slotting of the electrodes permits of a lateral movement thereof, so that the exact point of making contact with the electrode 26 can be adjustably attained which is necessary to cause the motor to function properly.

To the casing 10 there is secured a lug 34, Fig. 1, by which, and a rod 35, connected to the lug by a pivot 36, the casing can be oscillated so that rotating it in one direction, the moment of contact of the electrodes will be advanced, while a movement in the opposite direction will retard or delay the time of making contact to close the electric circuit, it being understood that the establishing of contact of the electrodes depends upon the rotative speed of the motor, and must be advanced as the speed of the motor increases.

In order to connect the rotor to the shaft 15, there is formed at the inner end of the hub 16, a slot 37, Fig. 3, and near the end of shaft 15, there is inserted a pin 38, a cap 39 being placed over the end of said hub to retain the pin 38 in position.

The inner end of the shaft 15 is reduced in diameter and the reduced portion is ex ternally screw-threaded to receive a locking nut 40. which holds the cap 39 to the shaft 15. This, however, does not lock the rotor to the said shaft, so that the rotor can be readily removed from the shaft when desired or found necessary, in an obvious manner.

As hereinbefore stated, the timer described is adapted for use on four-cylinder explosive engines. To enable this timer being employed on two-cylinder engines, all that is required is to remove two diametrically opposed contact electrodes: while for a three cylinder engine, three of these electrodes are used and then arranged 120 degrees apart. For an engine having more than four cylinders, the casing 10 will be correspondingly enlarged and the proper number of contact electrodes and their accessories installed therein.

It may finally be observed that the rotor with its single curved electrode 18, in conjunction with the curvature of the electrodes, is capable of rotating in forward and backward directions, so that the timer will correctly function whether the engine rotates in a forward or backward direction.

I have hereinbefore described the preferred embodiment of my invention, but I desire it to be understood that I am aware that changes in the details of construction may be made without departing from the scope of my invention as defined in the appended claims.

Having thus fully described this invenesa-e67 tion, I claim as new, and desire. to secure to myself by Letters Patent of the United States v 1; A timer for internal combustion engines, comprising, in combination, a casing. a multiplicity of electrodes in said casing, each of said electrodes being a substantially U-shaped blade, one of the limbs of said blade being arcuate, the convex side of the blade being in the direction of the center of the casing, the other limb of said U-shaped blade being slotted, a screw in each of said slots to secure said electrodes to the inner wall of said casing, a shaft in said casing and extending therefrom to connect with the aforesaid engine, a rotor removably connected to said shaft, said rotor having an extension, an electrode or brush pivotally connected to said extension, said brush being a curved blade the convex side of which is in the direction of the before-mentioned electrodes, said brush having means to limit its outward movement, and a spring in said extension and acting upon said brush to support it in outwardly extended position.

2. A timer for internal combustion engines, comprising, in combination, a casing, a multiplicity of electrodes in said casing, each of said electrodes being a substantially U-shaped element, one of the limbs of said element being decidedly curved, the convex side of the curve being in the direction of the axial line of said casing, the other limb of said element being slotted, a screw in said slot for securing said element to the inner surface of said casing, there being insulating washers upon each screw to insulate said U-shaped electrodes from said casing, a shaft in said casing and projecting therefrom to connect with the aforesaid engine, a rotor removably secured to said shaft, said rotor having an extension, an electrode or brush pivotally connected to a said extension, said brush being an arcuate blade, the convex side of which is in the direction of the said U-shaped electrodes, said brush having a tail constructed to contact with said extension to limit the outward movement of said brush, a spring in said extension and acting upon said brush to support it in outwardly extended position, and means for oscillating said casing.

3. A. timer including a casing, a plurality of contact-s on the casing, a rotary shaft disposed centrally of the casing and having a contact member to cooperate with the first mentioned contacts on the casing, the contact member on the rotary shaft comprising a continuous rigid metal plate pivotally connected at one end to said shaft, a portion of the plate being adapted to contact with the first mentioned contacts, and resilient means for pressing the outer contact portion of said contact mem ber outwardly, and each of the contact members on thecasingconsisting of a s ingle continuous substantially rigid metal plate having a' base portion at one end thereof secured to the casing, an intermediate outstanding part, and an outer contact portion disposed at an angle to said out standing part and spaced from said base portion, whereby a firm support for the said outer contact portion is afforded while providing for slight cushioning thereof to pre vent rebounding upon impact of the rotary contact member therewith.

4. A timer including a casing, a plurality of contacts on the casing, a rotary shaft disposed centrally of the casing and having a contact member to cooperate with the first mentioned contacts on the casing; the contact member on the rotary shaft comprising a continuous rigid metal plate pivotally connected at one end to said shaft, a portion of the plate being adapted to contact with the first mentioned contacts, and resilient means for pressnig the outer contact portion of said contact member outwardly, and each of the contact members on the casing being of general U-shape form constructed from a single continuous substantially rigid metal plate and comprising a base portion at one end thereof fixedly secured to the casing, an intermediate outstanding part, and an outer contact portion disposed at an angle to said outstanding part and spaced from said base portion, whereby a firm support for the said outer contact portion is afforded while providing for slight cushioning thereof to prevent rebounding upon impact of the rotary contact member therewith.

5. A timer including a casing, a plurality of contact members on the casing; a rotary shaft disposed centrally of the casing and having a contact member to cooperate with the first mentioned contacts on the casing; the contact member on the rotary shaft comprising a continuous rigid metal plate pivotally connected at one end to said shaft and having an outer curved contact portion, and resilient means for pressing the outer contact ortion of said contact member outward y, and each of the contact members on the casing consisting of a single continuous substantially rigid metal plate having a base portion at one end thereof fixedly secured to the casing, an intermediate outstanding part, and an outer curved contact portion disposed at an angle to said outstanding part and spaced from said base portion.

6. A timer including a casing, a plurality of contacts on the casing, a rotary shaft disposed centrally of the casing and having a contact member to cooperate with the first mentioned contacts on the casing, the contact member on the rotary shaft comprising a rigid metal plate pivotally connected at one end to said shaft, and resilient means for pressing the outer part of said contact member outwardly, and each of the contact members on the casing consisting of a single continuous substantially rigid metal strip having a base portion at one end thereof secured to the casing, an intermediate outstanding part, and an outer contact portion spaced from said base portion, Whereby a firm support for the said outer contact portion is afforded While providing for slight cushioning thereof to prevent rebounding upon impact of the rotary contact member therewith.

In testimony that I claim the foregoing as my invention, I have hereunto set my hand.

JOSEPH J. DOBES.

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