US2054016A - Ignition device - Google Patents

Description

S p 1936- v 1.. B. EHRLICH 2,054,016

IGNITION DEVICE Filed Aug. '7, 1934 2 Sheets-Sheet 2 "I," 3 0 314mm LOUIS B. EHELIQH FT-6 IT7 A Q g QMMW Sum/ma.

Patented Sept. 8, 1936 IGNITION DEVICE Louis B. Ehrlich, Toledo, Ohio, assignor toTho Electric Auto-Lite Company, Toledo, Ohio, a corporation of Ohio Application August 7, 1934, Serial No. 738,856

3 Claims. (01. 200-19) UNITED STATES PATENT OFFICE This invention relates to apparatus used with internal combustion engines, and more particularly to a timer and distributor mechanism included in the ignition systems for said engines.

The invention comprehends the provision of a sheet metal contact carrying lever or arm of exceedingly light weight, the construction including the minimum amount of material formed to a configuration capable of withstanding longitudinal and transverse stresses, whereby the contact carrying arm is possessed of small inertia and is capable of high rapidity of oscillation.

The invention comprehends the process of making a contact breaker arm or lever from very thin sheet material with the fewest possible number of operations producing a contact breaker arm of simple construction highly emcient for high speed operation.

Another object of the invention is the provision of a contact breaker assembly including the least number of parts forming a lever of simple construction, each part having long life and forming an assembly embodying the least practical amount of mass.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawings of a form'of the invention, which may be preferred, in which:

Figure 1 is a cross sectional view taken substantially through the center of the timer and distributor embodying the invention;

Figure 2 is a top plan view of a timer and distributor embodying the invention with the insulating cover removed;

Figure 3 is a view illustrating one step in the process of forming the breaker arm from a sheet metal blank;

Figure 4 illustrates another step in the formation of the breaker arm assembly;

Figure 5 illustrates another step in the formation of the breaker arm assembly;

Figure 6 is a cross sectional view taken substantially on the line 6-6 of Figure 5;

Figure '7 is a cross sectional view taken substantially on the line 1-1 of Figure 5;

Figure 8 is an elevational view of the breaker assembly of my invention;

Figure 9 is a cross sectional view taken substantially on the line 9-9 of Figure 8.

Figure '10 is a top plan view of the breaker assembly illustrated in Figure 8;

Figure 11 is an enlarged cross sectional view taken substantially on line H-ll of Figure 10.

I have illustrated my invention as incorporated in a combined timer and distributor mechanism suitably used for internal combustion engines, but it is to be understood that I contemplate the use of my invention wherever the same may be found to be applicable.

Referring to the drawings in detail, the operative parts of the timer and distributor of my invention are suitably enclosed within a cup-shaped housing 20 which is provided with 8. depending shank 22 by which the timer is supported to a frame of an engine (not shown). The cup-like portion of the housing 20 removably carries a distributor head 24 of suitable insulating material such as a phenol condensation product which in turn supports an insulating cap 25. Shank 22 is formed with a central bore providing a bearing for the ignition timer driving shaft 21 adapted to be actuated by the internal combustion engine by means of a driving coupling 29 fixedly secured to shaft 21. The drivingshaft 21 is provided with a reduced portion 3| upon which is fixedly secured a plate member 34 located within housing 20 resting upon a central projection 32 formed on the inner surface of base portion of housing 20. Plate 34 supports a plurality of weights 36 acting as centrifugal spark adjusting means each of the weights being formed with pins 38 and 39 adapted to engage suitable openings in a member 40, which in turn is secured to a sleeve 42 iournalled upon the reduced extension 43 of the drive shaft 21, the sleeve 42 being driven by shaft 21 through the use of the centrifugal adjusting means.

Suitably carried by sleeve 42 is a cam member 45 provided with a plurality of lobes 46 which in the present instance is showing as comprising eight lobes. The portion of the sleeve 42 designated as 41 which extends above cam member 45 removably supports the distributor rotor 49 preferably made of a high dielectric material such as a molded phenol composition. Distributor rotor 49 is provided with a non-circular bore tin-which snugly fits the end portion 41 of sleeve 42 and serves as a positive driving connection therebetween. The central end portion 41 of sleeve 42 terminates into an enlarged opening adapted to accommodate a wick 5| or other lubricant retaining means, this opening being closed by the main body portion of the distributor rotor 49. Fixedly secured to distributor rotor 49 by any suitable means such as a rivet 52 is a current conducting plate 54. Plate 54 is engaged by brush 56 urged into positive contact by means of a spring 58 both of which are supported within a central opening 59 formed on a metallic insert Si or terminal em= bedded on the vertical boss of horizontal wall 63 forming part of distributor head 24. Metallic insert Si is provided with an extension 65 terminating into a threaded portion 66 both adapted to pass through a central opening 61 formed on projecting boss 69 of distributor cap 25. The threaded portion 66 coacts with a threaded member embedded on a knob 88 of insulating material serving to secure a high tension terminal and also to retain cap 25 in tight engagement with distributor head 24. Distributor cap 25 is formed with enlarged projections III acting as clamping means for securing the spark coil cables (not shown) into engagement with prongs 12 forming part of metal insert 13 embedded on the horizontal wall 63 of insulating material and located in a circular track adjacent to the outer wall of distributor head 24. Metal inserts I3 are provided with a depending portion I5 which lie in close proximity to the circular path of travel by the end portion 11 of conducting plate 54 carried by the distributor rotor 49 so that the high tension current or spark impulses conveyed to terminal BI are conveyed by conducting plate 54, insert 13 and hence to the proper engine cylinders. The distributor unit comprising head 24 and cap 25 are removably retained in position on cup-shaped member 20 by a pair of spring clips 18 and I9 pivoted on suitable bracket secured to the outer wall of member 20.

The inner surface of the lateral walls of housing 2B is formed with a ledge.8l upon which is supported by its peripheral edge a circular plate 82 provided with a central opening, through which projects the sleeve 42 carrying the cam element 45. Plate 82 separates the housing into two compartments or chambers enclosing the governor mechanism and the timer and distributor mechanism respectively. Suitably secured to plate 82 is the circuit interrupting mechanism which due to the rotation of the cam 45 produces the periodic interruption of the primary circuit of the ignition coil. The interrupting mechanism comprises a stationary contact 83 preferably of tungsten or other suitable material welded to or suitably carried on threaded member 84 which in turn is adjustably supported on a threaded opening formed on an L-shaped bracket 86 which is fixedly secured to plate 82 by means of a rivet 87 thus forming a suitable ground for the stationary contact 83. In the present instance, the stationary contact 83 is locked into adjusted position in the threaded opening of bracket 86 by means of a lock nut 89 threaded on member 84.

The stationary contact 83 is engaged by a movable contact 90 made of tungsten or other suitable material welded to a pivoted lever 92 formed of thin sheet steel or other hard metal and including a longitudinal reinforcing rib or central fold 93 having lateral extending side walls 95 forming a substantially channel-shaped section from its central portion towards its pivotal point. Fixedly secured or retained to the web portion or back wall 91 between the side wall 95 is a rubbing block 98 adapted to be engaged by the cam lobes 46. The side walls 95 of lever 92 are provided with aligned openings 99 held in spaced relation by a bushing I III in which is snugly retained an insulating bushing I02 which serves as a pivotal bearing support for the arm about a pivotal post I03 fixedly secured to plate 82. The movable contact 90 is urged into engagement with stationary contact 83 by means of a spring I04, one end of which engages the rear portion of web 91 oi. the channel section of the breaker arm 92 partially surrounding thespacing bushing IOI and having its other end in engagement with a vertical extension or projection I05 forming part of the primary circuit terminal IIi'I which projects from housing 20, being insulatingly carried by the stationary plate 82.

For the purpose of guaranteeing an efilcient connection reducing the electrical resistance to the flow of currentto a minimum between the movable contact 90 and the circuit terminal I01, a strip III) of good current conducting material such as copper is secured to the web portion 9? of the breaker arm 92 by the rivets M2 and IIB. which also serve to retain the rubbing block 98 in fixed position to the breaker arm. The other end of the current conducting strip is retained into engagement with vertical extension I05 of circuit terminal ID? by means of a screw I I4 which, in the present instance, retains one end of the spring member I04 and at the same time serves to provide a circuit connection between one end of condenser III, the other end of which is in electrical connection with plate 82. Thereby, when the movable contact 90 is moved out of engagement with contact 83 by the cam 46, to interrupt the primary circuit, the condenser forms a parallel connection with stationary contact, thus preventing undue arcing of the contacts.

The method of producing the assembly adapted to carry the interrupter contact 90 which is actuated by the cam will be hereinafter described and includes the formation of a breaker lever or contact carrying member from a sheet of thin material punched to produce a blank of a substantially triangular configuration as illustrated in Figure 3 of the drawings, this blank is thus formed by suitable dies to include a longitudinal fold 93 along its medial line, in order to increase its strength and rigidity. The blank is also slightly bent as at I20 for the purpose of reinforcing the end portion I22 upon which is adapted to be secured the interrupter contact 90. In the process of making the breaker arm, another step consists in forming at each of the corner portions I28 and I 24 of the triangular blank spaced openings 99 and decreasing the width of arm surface from substantially the central portion to the end portion I22 as illustrated in Figure 4.. Side portions of the blank thus shaped are bent along dotted lines I25 and I 26 in order to form the parallel side walls 25, causing the accurate alignment of openings 99, so that the same will be adapted to receive thepivotal elements hereinafter described. This step in the formation of the arm assures that the same will be shaped to a substantially channel-shaped cross-section from its central portion to the end on which are located the aligned openings 99 as shown in Figure 6 of the drawings, the remaining portion of the breaker arm, form its center portion to the end portion I22 is of a substantially T cross-section as particularly illustrated in Figure '1. To the T cross-section of the breaker lever adjacent to the end portion I22 is secured the circuit contact 90, which is preferably made of a tungsten or other suitable substance capable of withstanding the mechanical stresses as well as the deleterious effects caused by the rapid and periodic interruption of the flow of current in the primary circuit. Circuit contact member 90 is preferably secured to the end portion I22 of the breaker lever by brazing the same to the T-shaped cross-section thereby causing that the bonding or bracing material I20 will flow in the small center groove I29 caused by the contiguous walls of the webs 91 forming the central fold 03. The bonding material I20 serves the dual purpose of securing the contact 90 to the breaker lever wall and at the same time binding together the integral adjacent walls forming the central fold 83, so that any possibility of relative movement between these walls when the breaker arm is operated at high speed is entirely eliminated and due to this fact is capable of withstanding laterally and longitudinally without binding or putting the same out of shape.

After this operation is performed, the L-shaped rubbing block orv suitable cam follower and the flat strip of conducting material H0 are secured to the breaker arm wall 01. This cam follower is preferably of an L-shaped formation and is made of a fabric permeated and stiffened with a condensation product. The rubbing block 00 and strip of material IIO are provided with openings adapted to receive securing means in the forms of rivets H2 and III which are preferably spun to the rear face of the web or back wall 01 adjacent to the rib formed by fold 93. This spinning of rivets will prevent undue stress on the rubbing block 90 eliminating any possibility of breaking the same while this operation takes place, and also will serve to provide an intimate contact between the flat strip H0 and the inner face of the web portion 91 of the breaker arm. By this arrangement single means are used to secure the cam follower 08 and conducting strip H0 in position, the arrangement providing very compact grouping of the elements of the structure, decreasing the parts to a minimum without affecting in any way their efficiency in operation.

In order to retain the side walls 95 in proper parallel relation and provide suitable pivotal means for the breaker arm, a spacing and reinforcing bushing IOI made of aluminum or other light material is located in the openings 99, the

bushing I0i being formed with recesses I30 and I3I as particularly shown in Figure 11, and adapted to have portions adjacent to said recesses swaged over the side walls 95 in order to retain the same in proper position and prevent any relative motion therebetween.

In the particular embodiment illustrated, the breaker arm carrying the contact 90 is suitably insulated from the rest of the structure and for that purpose suitable insulating means are used in the form of an insulated bushing I02 adapted to snugly fit the opening formed in bushing IOI, thus providing a bearing of suitable insulating material forthe breaker arm. In order to prevent relative motion between spacing bushing IM and the insulated bushing I02, the inward walls of bushing IOI are formed with longitudinal recesses or serrations I33 so. that when bushing I02 is forced into position, these recesses will serve as interlocking means for preventing relative motion between bushings I0! and I02. In carrying out the method of producing the breaker arm, the same is placed in a matrix in order to burnish or grind the contact face I 35 of the rubbing block 98 so that the same is absolutely in true and parallel reaction with the contact member pivotal axis in order to provide a very eflicient surface of contact between the rubbing block and cam actuating element. It should be noted that the slight bend provided in the breaker arm as indicated in Figure 3 as at I20 aids in the successful operation of the breaker arm and is dependent upon the overall dimension of the breaker arm. I preferably locate this bent portion about th of the length of the breaker arm measuring from its pivotal axis to the center of the surface of the tungsten contact member 80.

From the foregoing it should be noted that I have produced a breaker arm of a very thin ma- ;terial of extremely light weight forming an assembly where the amount of mass is decreased to a minimum, whereby the hammer action caused by opening and closing of the arm by the cam member is decreased materially and the breaker arm weight is such that the reactive forces acting on centrifugal means for controlling the proper timing of the spark are reduced to a minimum, thereby producing a very eilicient and reliable device. It should be noted that by the particular arrangement of parts and the method of forming the breaker arm, very thin soft sheet material could be used and due to the formation of the breaker arm and the peculiar arrangement of its component parts, the lever is exceedingly rigid in all directions, retaining its shape under all conditions of operation.

Associated with the breaker arm assembly, which process has hereinbefore been. described, is a spring member I04 which serves the purpose of urging into engagement the interrupter contact 90 carried thereby into engagement with the stationary contact 83. Spring I04 is provided with a bent end portion I06 having an open ended slot of suitable width to snugly fit the side walls fold or rib 93 of the breaker arm assembly and the spring is shaped so as to partially surround the pivotal post upon which the breaker arm is journaled. The other end of spring I04 is provided with suitable openings adapted to receive screw I I4 for retaining one end of the spring I04 to the projection I05 forming part of the primary circuit terminal I01. This arrangement will assure that the spring I04 will be under tension tending to oppose the movement imparted by the cam lobes 46 of rotary cam 45 of the timer and distributor. Spring member I04 is preferably made of spring steel of suitable material tempered and shaped to the configuration particularly illustrated in Figures 9 and 10 of the drawings. The breaker arm including the spring member forming the unitary assembly can be easily removed and replaced from the timer and distributor by loosening or unscrewing the threaded member II4 from projection I05 thus permitting the ready substitution of the spring or of the breaker lever assembly for the timer and distributor.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

What I claim is:

1. A breaker arm for an ignition device including a member made of sheet metal having a web connecting parallel sides, said sides being provided with aligned openings at one end and a laterally projecting rib formed on the web portion of said member extending substantially the length thereof. Y

2. A breaker arm including, a member of thin sheet metal including a portion formed to a channel-shaped configuration provided with aligned openings at one end; a reduced portion adapted to carry a contact member and a reeniorcing fold formed on the back wall and extending substantially the length of said member.

3. A breaker arm for an ignition device including. a member formed of sheet metal including a portion formed to a substantially channel-shaped configuration having openings on its side walls at one end; a reenforcing rib extending longitudinaliy on the back wall of said sheet metal body forming a portion of a substantially T- shaped cross section adapted to carry a contact at the end of said section.

4. A breaker arm assembly for an ignition device including, an arm of sheet metal provided with openings at one end and a contact at the other end; an intermediate cam engaging member fixed to the back wall of the sheet metal arm and snugly retained by side walls formed on said am; and a re-enforcing rib projecting laterally from the back wall of said arm.

5. A breaker arm assembly for an ignition timer including, a member made of sheet metal aligned openings; 9. contact carried by said weblocated at one end thereof a cam engaging element located between the bent portions of said member; a laterally projecting rib formed on the web of said member extending substantially the length thereof; a conducting strip interposed between said cam engaging member and said web; and common means for securing said strip and said element to the web of said member.

6. A breaker arm assembly for 'an ignitiontimer including, a member of thin sheet metal including a portion formed to a channel-shaped configuration having openings at one end of the side walls of said configuration; a reduced portion formed at one end of said member; a contact secured to said reduced portion; a cam engaging element secured to the back wall and being 10- cated between the sides of said channel-shaped portion; a re-enforcing fold formed on the back wall and extending substantially the length of said member; and a metallic bushing located on said openings for retaining said side walls in proper spaced relation.

7. A breaker arm assembly for an ignition timer including, the combination of a fixed contact; a pivoted breaker arm carrying a contact cooperating with said fixed contact, said breaker arm being formed from a sheet metal blank, a portion of which is bent to a channel-shaped configuration; a longitudinal reinforcing rib formed in the back wall of said arm; a block of insulating material secured to the back wall of said arm between the laterally extending walls; an actuating cam cooperating with said block to move said arm; and a flat spring partially surrounding the pivotal point of said arm and having one end in engagement with the back wall thereof for opposing the movement of said arm by said cam.

8. A breaker arm assembly for an ignition timer including, the combination of a breaker arm formed of sheet metal provided with aligned openings, said arm having a portion of substantially channel-shaped cross section including a reinforcing longitudinal rib centrally located on the back portion of said channel-shaped portion; a block of insulating material adapted to engage the back and side walls of said channelshaped portion; a contact carried by one end of said arm; and a sleeve passing through the aligned openings of said arm.

LOUIS B. EHRLICH.

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