US1686686A - Ignition timer - Google Patents

Description

Oct. 9, 1928. 1,686,686

T. A. EDISON, JR

IGNITION TIMER Filed Oct. 19. 1922 Ewvautoz v h abhor w Patented Get. 9, 1928.

*UNIT'ED STATES PATENT OFFICE.

THOMAS A. EDISON, JR, 011: ORANGE, NEW JERSEY, ASSIGNOR TO THOMAS A. EDISON,

' INCORPORATED, or WEST ORANGE, NEW

JERSEY, A CORPORATION OF NEW JERSEY.

IGNITION TIMER.

Application filed October 1 invention relates to devices for closing the electric circuits of the several spark plugs of multi-cylinder internal combustion engines, which are generally referred to as. signition timers.

One of the principal objects of my invention is to insure the correct andconcentric positioning of the timer casing and the contacts carried thereby with respect to thetimer 1:) shaft of an internal combustion engine, regardlessof any eccentricity of the timer recess in the engine frame with respect to said shaft. I

My infention further resides in an im- 15 proved arrangement and improved features of construction for ignition timers, whereby the wear and the likelihood of breakage of various parts are reduced to a minimum, and whereby when the timeris in operative. posi- 113 tion the effective grounding of the contact member of the rotor to one set of terminals of the spark plugs is assured at all times. v

Further objects of my invention are to reduce the friction, in the movable parts of this type of ignition timers to'a minimum, to effect afcontacting engagement between the contact member of the rotor and the fixed spaced ontacts cooperating therewith which constantly shifts to different surface points of both the contact member and contacts, and to provide for the ready replacement of those parts of the timer which are .most' likely to wear. g 1

Other features of my invention reside in the construction ofparts and combinations of elements hereinafter more fully described and claimed. v r i For a clearer understanding of my invention, attention is directed to the following descriptioinin connection with the drawing accompanying and forming a part-of this SpGfilfiCtlllOll and in which: I

Figure 1 is a view in rear elevation, partly in section, of one form of ignition timer in accordance with my, invention, with the adapted means omitted; I

Fig. Qisa sectional View, partly injelevation, showing the timer applied to the engine housing, the scctionjbeingtakenon a line corrcs 'ionding to line 2-2 Of'F1g. 1;'

Fig. "in rear eleu is a fragmentary'vlew ration of the timer provided withthe adaptor or locating and centering meanst i Fig. 4 is an enlarged viewqin elevation, M partly in section, of a modified form of con- 22. serial No 595,525.

tattwhich may be used in place ofthe fixed spaced contacts of the construction shown in Figs. 1 and 2; and y V Fig. 5 is a plan View of the contact shown in Fig. 4. I I

Referring to the drawing, reference character 1 represents the timer casing, which is cylindrical in form and which is mounted for oscillatory movement on the engine'housing 2 in a special manner, presently to be described. enabling the same and the spaced contacts carried thereby to be positioned absolutely concentrically with the timer actuating shaft 8 and insuring the maintenance thereof in such concentric position in the various angular adjustments made in advancing and retarding the spark. The timer casing 1 is provided at its front end with a cover 41, preferably formed integrally therewith. The timer shaft 3, driven by suitable gearing (not shown) in synchronisin with the engine shaft, is journaled in a suitable bushing 5 within an opening in the. engine housing 2, and extends from the latter into the timer casing 1. The cover 4 of the timer casing is formed with a central forwardly extending portion 6. into which the end of the timer shaft 3 projects. This portion 6 of the cover 4 is provided with a recess 6' forming a seat for the usual spring (not shown) employed to hold the timer casing 1 in proper position with respect to the engine housing 2. g

The portion of the timer shaft 3 extending into the timer casing is reduced, and an eccentric 7 is secured to suchfreduced portion of the shaft as by means of a pin 8 extending through the hub of the eccentric and into the shaft. A sheet metal cap 9 takes over the end of the hub of the eccentric 7 and the head of pin 8 and acts as a retainer to hold the latter in place. A nut 10 is threaded onto the end of shaft 3 and a spacing sleeve or bushing 11 is mounted on the reduced end portion of the shaft between the shoulder formed by such reduced portion and the eccentric 7. The nut 10, of course, holdsthe retainer 9 in place,

and when tightened coactswith the shoulder on shaft 3 to rigidly secure the eccentric 7 and spacing sleeve, 11 to the shaft to turn therewith. Mounted on the eccentric? so that the latter is capable of free rotary movement with respect thereto, is acontact ring 12. In order to reduce the friction between the eccentric 7 and the ring 12, a rollerbearing,,

preferably a ball bearing 13, is disposed between the said ring and eccentric, the outer and inner raceways of such bearing preferably being respectively provided on the inner and outer opposed walls or peripheral surfaces of the ring 12 and eccentric 7. The contact ring 12 cooperates with a plurality of contacts 11 of special form, which are carried by the casing 1 and equi-spaced about the axis of the shaft The cylindrical casing 1 is provided on its inner side with equi-spaced integrally formed projecting portions 15 crresponding in number to the contacts 1 1 and having flat inner faces. Each of the contacts ll comprises a headed metallic member 16, the shank of which extends through one of the inwardly projecting portions of the casino 1 and the wall of the casing, and the polygonal head of which bears against the inner flat face of said portion 15. The outwardly extending end portion of the shank of thehcaded memb r 16 is threaded, and a nut- 17 turned up on such threaded end portion tightly against an outer flat surface portion provided on the cylindrical wall of the casing 1, serves to rigidly secure the contact to the latter, as shown in Figs. 1 and 2. The usual conductors (not shown) respectively leading from one set of terminals of the spark plugs are respectively adapted to be connected to the contacts l l between the nuts 17 and nuts 18 threaded on the outwardly extending end portions of the members 16. Each of the contacts 14 also comprises a pair of similar fiat springs 19 and 20 firmly secured together at one end so that they will be in soaced and substantially parallel relation, as by means of a pair of spacing pins or rivets 21, each having reduced end portions which respectively extend through the springs 19 and 20 and are peaned over as indicated at 22. The spring 19 is firmly secured at its other end to the head of the headed member 16 of the respective contact 14, as by means of an inwardly extending reduced portion formed on said h ad, which extends through spring 19 and is peancd over as indicated at The corresponding adjacent end of the spring 20, which is spaced inwardly from the headed member 16, is free and carries on its inner side a metallic contact button B, the latter being firmly secured to spring 20 by means of a reduced portion formed on the button which extends through the spring and is peaned over as indicated at 21. The contacts 1 1 are preferably secured to the wall of the casing 1 in the posi ion shown, with the springs 19 and 20 of each contact extending ithin the casing from the headed member 16 supporting the same, in a direction opposite to that in which the timer shaft 3 and eccentric T are rotated, the direction of rotation of the latter, looking at Fig. 1, being clockwise. The timer shaft 3, eccentric 7, contact member or ring 12 and bearing 18 are all formed of conducting material and are grounded to the engine frame or casing 2, and are accordingly electrically connected with the other set of terminals of the spark plugs, which are likewise grounded to the engine frame. The casing 1 is formed of suitable insulating material, preferably a phenolic condensation product such as condensite or bakelite, and it is therefore unnecessary to provide insulating bushings for the headed members 16 of contacts 14-. in order to insulate the latter from each other. I

lVith my improved timer properly applied in operative position, as shown in Figs. 1 and 2. it will be apparent that as the timer actuating shaft 3 is rotated, by the operation of the engine, the eccentric 7 connected to this shaft will cause the contact member or ring 12 to successively en age and disengage the contact buttons B of the contacts Ll at the central portion of their inner convex surfaces, to thereby successively open and close the corresponding spark plug circuits at the proper time. As the eccentric 7 is capable of free rotary movement with respect to the contact ring 12, the movements imparted to the latter towards and from the successive contact buttons B will be radial, or at least the major components of such movements will be radial. As a matter of fact, when the timer is operated, the rollers or balls of the bearing 13 slip somewhat on the raceway of the eccentric 7 and tend to rotate the ring 12 in a direction opposite to that of the shaft 3 and eccentric 7. and in the absence of any means to retard or impede rotary movement of the.contact ring under the action of said rollers or balls, this ring would actually rotate at an appreciable speed, much less however than that of the shaft 3 and eccentric 7, in a direct-ion opposite to the eccentric. However, 1 preferably provit suitable means for retarding such rotation of the contact ring 12 so that the same will rotate as described only at an exceedingly slow rate. This means as shown comprises a thin resilient member or arm 27 formed of conducting material such as thin spring steel or other resilient sheet metal. The member or arm 27 is secured at one end, as by one or more rivets 27, to the conductive plate 33 of the adapted means, presently to be described, for locating and centering the timer casing with reference to the axis of the timer shaft 3. The member 27 extends diametrically of the timer casing and is provided intermediate its ends with an enlargement having a circular opening 28 somewhat larger in diameter than the sleeve or bushing 11 and through which, when the timer is assembled, said sleeve and the shaft 3 loosely extend as shown in Fig. 2. The arm 2'? is bent sui'iiciently so that it tends under its own resiliency to normally assume a position with its free end 29 some vha to the right of where it is shown in Fig. 2.

Accordingly when the timer is assembled,

lLIll a replaceable contact piece 40 for engagement with the contact ring. This contact piece 40 is formed of thin resilient sheet metal, is preferably circular, and has a pair of spaced spring fingers or tabs 41 stuck therefrom betweenwhich and the main body portion of the contact piece'the end 29 of arm 27 is adapted to be received. The fingers 41 lie so closely to the main body portion of the con tact piece that when the latter is slipped onto the end 29 of arm 27 to the position shownin Figs. 1 and 2, such fingers will be forced or sprung outwardly and will accord ingly act to frictionally grip the arm 27 so as to prevent any displacement or movement of the contact piece with respect to the arm' in the operation of the timer. Should the contact-piece 40become appreciably worn it may be readily and quickly replaced. While it is advisable under somecircumstances, to employ the contact piece 40, the latter is, of course, not essential to the successful operation of thetimer. y

The contact effected between the 12 and the contactbuttonsB of my improved timer, as distinguished from the timers now on the market, is practically non-wiping and nonrolling and may be aptly termed a bui'nping contact. The very slow rotary movement of the ring 12 during the operation of the timer suffices, however,to insure a constant shifting ofthe points in the contacting surface of the ring where the buttons 13 intern'iittently engage the ring, and accord- ,inglythe ringwill not become pitted or burned as might happen in case each of the buttons 13 successively made contact there with onlyat a givenpoint in the contacting surface thereof;

The use of contacts 14 of thespecial construction shown and described herein, results in a number of advantages. The springs 19 and'20 are without bends and may be readily treated to bring the sameto' a high and uniform temper. Moreover, by 'reason of the connection of the respective pairs of springs 19 and20 to each other at one end and to the headed members 16 and the contact buttons B respectively at the other end, the bending strains IBSUltiIlgfIOHl the engagement of the buttons B by the ring 12 in the operation of the timer, will be divided by the springs.

Consequently, the bending strains towhich each of the springs 19 and 20 is subjected will be slight, and the likelihood of the springs crystallizing and breaking in the tance throughwhich the latter is moved by the ringgradually lessen. It is to be understood, of course, that by reason of the bumptact buttons'B, the wearing of these buttons just referred to, even for a long period of operation of the timer is but slight.

In place of the contacts 14 of the construction shown in Figs. 1 and 2, I prefer to employ contacts of the form shown in Figs. 4 and 5. In the contact 14 of Figs. 4 and 5, the headed member 16, flat springs 19 and 20, and the spacing pins 21 are, ofthe same construction and arrangement as the corresponding elementsof the contacts 14 shown in Figs. 1 and 2, except that the spring 20 is provided at its free end with an open-ended slot 42.1 The reduced ends of the pins 21 which extend through the flat springs 19 and 20 at one end are peaned over at 22 to secure these springs rigidly together in fixed spaced relation at said end, and the head of member 111g engagement of the ring 12 with the con- 16 is providedwit-h a reduced projection v extendingthrough the other end of spring 19 and peaned over at 23 to rigidly secure said memberi'and springtogether- A fiat spring 20", similar to spring 20, is secured at one end on the reduced end portions of pins 21 between the shoulders formed by such reduced end portions and the spring 20 The s rin 20is rovided ad'acent its other or P a P l free end with a circular opening 44. The

s rin 20 tends under its own resilienc to.

assume a position in which it lies closely against the spring 20 throughout its length. The contactbutton B of each contact 14 is of the same general form as the contact butvex contacting side or surface, is provided with a cylindrical projection or stem 43, the diameter of which is less than the diameter of hole 44 in spring 20", and also slightly less than thewidthof slot 42 in spring 20. The stem 43 is provided intermediate its ends with a cylindrical enlargement or collar 45. To apply the button B in place as shown in Fig. 4,'it ismerely necessary tozpress and hold the free end of spring 20 a considerable distance from the corresponding end of spring 20','t-o then slide that portion of stem 43 of the button between the collar 45 and the head of the button into the slot 42 until it engages the end wall of the slot, and to thereupon release the free end of spring 20. Upon so releasing the free end of spring 20", the latter will immediately move or spring into engagement with the collar to, with the opening it therein taking over the outer end portion of stem 43 on the button. It is apparent that the button, by reason of the engagement of stem l3 thereof in the circular opening of spring 20", will be firmly held or locked a ainst displacement when the timer is in operation. Moreover, by reason of the width of slot a2 and the diameter of opening ll being greater than the diameter of stem iii, the button B is rotatable on its mounting. Accordingly, when the button is engaged by the contact ring 12 in the operation of the timer, said ring will, because of its slow rotary movement, tend to rotate the button. As a matter of fact, this action of the ring 12 on the button B effects a very slight angular movement of the latter on each engagement, with the result that the button presents a constantly changing point of contact to the ring 12. Accordingly the wear and pitting of the contacting surfaces of the contact buttons, when contacts of the form shown in Figs. l and are employed, are reduced to a minimum. In case any of these buttons become worn, pitted or otherwise damaged to such an extent to impair the operation of the timer, the same may be quickly replaced by a new button. To do this it is merely necessary to press the free end of spring away from spring 20 a distance suflicient to disengage the stem d3 from the opening ll, remove the button by sliding the same laterally on the spring 20 until the stem l3 is disengaged from the slot 42, and to then insert a new button as described above.

The timer casing 1 is provided with an outwardly extending arm or bracket 25, prefen ably formed or molded integrally therewith, having a recess 26 adapted to receive one end of the usual rod or link, not shown, to effect angular adjustment of the timer casing in either direction about the axis of the shaft 3 for the purpose of retarding or advancing the spark.

Reference character 30 (Fig. 2) represents the usual circular recess provided in the engine frame as a seat for the timer casing. This recess, especially in the case of Ford cars, is very frequently slightly eccentric to the axis of the timer or cam shaft 3. Accordingly, I have designed a novel and simple adapter means which, when the timer is seinbled in operative position, as shown in Fig. 2. properly locates the timer casing 1 and maintains the same absolutely concentric with the axis of the timer shaft 3 with the buttons B of the contacts 14: carried by the equidistant from said axis, tnereby compensating for any such eccentricity of or projection 32 to ht somewhat loosely in he timer recess 30,

and a circular locating plate 33 of conductive :1 .i' "ii h a central opening in which the .rical bushing or sleeve 11 is adapted t: ve y closely, the ring 31 and plate 3 l connected, as shown, by a pair of scre at which extend through openings 35 lie plate ant are threaded into the ring. Elie openings 2-35 are preferably circular and, while less in diameter than the heads of the screws 34-, are considerably greater in diameter than the shanks of these screws, and accordingly upon loosening the screws, the ring 31 and plate 33 may be relatively adjusted. inst plate is adapted to fit very the open end of the cylindricas ng 1, as indicated at 36, and to ist the adjacent end surfaces of the g portions 15 to form a closure for To enable the timer casing l to j in the correct angular position, so to cause the adapter means to turn the 'i when the latter is adjusted to advance or retard the spark, the casing 1 formed on the casing, and the is provided with a radial open recess 38 with which the pin 37 is adapted to engage.

in installing or assembling my improved timer in operative postion, the cylindrical bushing or sleeve 11 is first slipped onto the reduced end portion of the timer or cam shaft 53 against he shoulder thereon. The screws 3% connecting the ring 31 and plate 38 of the adapter means are then loosened and the latter is placed over the shaft and the ring 31 and plate 33 thereof adjusted so that the annular projection 32 of the ring seats within the timer recess or seat 30 on the engine iiousing 2 with its slot 38 in a predetermined a: gular position, and so that the central opening in the plate is engaged by the bushing or sleeve 11. after which the screws 34 are tightened. The rotor, comprisingeccentrio 7. contact ring 12 and the ball bearing 2, next placed on the shaft 3 with the said 1Q';..11;' against the end 29 of the spring :cr 2'? or the removable wear piece 40 carried by said member, and is fastened to the pin 8. after which the pin retainer cap or 9 is slipped over the shaft 3 into operat've position and the nut 10 is applied tions of the latter. The free end of the usual spring arm (not shown) for holding the timer casing in position is now seated in the recess 6 of the cover 6 of the timer casing and the spring tightened, the end of the rod (not shown) for advancing and retarding the spark is engaged with the recess 26 .ot the bracket of the timer casing, and the wires or leads from the spark plugs are respectively connected to theproper contacts 14 between the-nuts 17 and 18.

In advancing and retarding, the spark, it will be apparent that the casing 1, adapter ring 31 and locating plate 33 will be turned together about the axis of thetimershaft However, the maximum angular movement of these parts in adjusting the spark is approximately twenty degrees, and the annular projection 32 of the adapter ringfl'll does not fit the recess with sufficient tightness to result in binding upon such movement.

It is to be especially noted that contact ring 12 isgrounded to the frame 2 at the seat 30 and outwardly'oi the shaft 3 through a direct path including the sheet metal spring member 27, and the conductive means engaging said sheet and comprising the locating plate 33 and adapter ring 31, as well as through bearing 13, eccentric? andshaft 3. Consequently, should the electrical connection between the ring 12 and eccentric 7 become impaired in any way as by presence or accumulation of oil, dirtor other foreign matter in the bearing 13, the ring would still bein good electrical connection with one set of terminals of the spark plugs.

It is to be understood thatthe construction shown and described herein is subject to various modifications and changes in the size, shape and arrangement of parts, without departing from the spirit of my invention or the scope of the appended claims.

Having now described my invention, what I claim as new and desire to protect by Letters Patent is as follows:

1. The combination with an internal combustion engine having a rotary element and a recess provided in the engine frame substantially concentric with the axis of said element, and a timer casing carrying a plurality of radially arranged, spaced contacts and adapted to be applied to said frame with said contacts in cooperative relation to said rotary element, of adapter means for insuring the concentric positioning of the timer casing and the contacts carried thereby with respect to the axis of the rotary element, said means comprising a pair of adjustably connected members one of which is adapted to take within and coact with said recess and the other of which is adapted to fit closely within the timer casing and over said rotary element.

2. In an ignition timer, a casing, and a contact carried by said casing comprising a member having an open-ended slot, a contact element having a head and a shank, said i shank having a collar intermediate its ends, said contact element being mounted on said member with that portion of itsshank above said collar engaging said slot, and a resilient member connected at one end with said slotted member and having an apertured free end, the apertured end of the resilient member normally being held under the resiliency of such member in engagement with the lower end of the shank of the contact member, substantially as described.

This specification signed this 18th day of Oct, 1922.

THOMAS A. EDISON, JR.

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