US2040106A - Ignition timing apparatus - Google Patents

Description

IGNIT ION T IMING APPARATUS Filed Oct. 8, 1931 INVENTOR BY JOHN d Eoaa Patented May 12, 1936 UNITED STATES PATENT OFFICE Application October 8,

24 Claims.

(Granted 1931, Serial No. 567,602 (Cl. 200-27) under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

5 The present invention relates generally to ignition timing apparatus, more particularly to improvements in circuit interrupters, or circuit breakers as they are generally called, used for making and breaking an electric circuit in the ignition system of an internal combustion engine; more specifically in structural character and operation the present invention has reference to and closely resembles in character that type of circuit breaker shown in my co-pending application Serial No. 326,056, filed December 14, 1928, also my co-pending joint-application Serial No. 116,360, filed June 16, 1926, generally referred to therein as the pivotless breaker mechanism adapted for regulating and controlling the timing of the ignition circuit in an internal combustion engine.

The primary object of the present invention is to provide in an electric circuit breaker of the pivotless breaker type referred to hereinbefore, improved means for'supporting the fixed ends of the breaker contacts, making it substantially an integral molded unit construction to thereby effect a more rigid and secure method of obtaining and maintaining correct alignment of the breaker contacts, providing a simpler mechanism, positive and more effective in operation,

properly safeguarded whereby the same may against short circuiting be manufactured at relatively small cost without sacrifice to quality and. I

35 whereby the mechanism may be easily assembled and readily disassembled and renewals quickly and cheaply effected.

- A further object of the present invention is to provide a circuit breaker of this" character, in which the movable contact arm of the breaker mechanism is adapted to make line contact with the rubbing block or cam follower at substantially the mid-portion of said contact arm so as to pre vent irregularities in the movement of the cam follower brought about by uneven wear on the cam. follower or cam surface from being imparted to the movable contact arm. This improved construction prevents torsional stresses being imparted to the movable contact arm during the make and break period and results in a clean instantaneous separation of the contact points, eliminating substantially all the rubbing action which might otherwise occur between the contact points during the make and break perlodso that the efliciency of the current charge generated in the system will be maintained.

A further object of the present invention is to so mount a wick or other equivalent lubricating means relative to a rotary cam or cam surface that 5 the wick or other lubricating means will be securely held in place, said means being interposed I between the rotating cam and contacts and forming a baflle so that lubricant thrown off from the cam surface by centrifugal action, which same might otherwise interfere with the proper functioning of the contacts will be readily absorbed by the wicking material. a

A further object of the present invention is to provide in a breaker mechanism of this character a rotating cam with suitable means which not only prevent lubricant from accumulating in front of q the cam follower, but also efiects a uniform distribution of lubricant at all speeds to minimize wear.

The invention is further characterized byproviding a. breaker mechanism of this character in which the cam follower is interposed between the supporting member of the breaking mechanism and the contacts so as the make and break period for a given'lift of cam follower. This feature is of particular importance in connection with battery ignition systems because of the limited amount of lift that can be acquired on a battery ignition cam, which normally has a greater number of lobes than cams used in connection with magneto systems.

With these and other objects in view, the invention consists in the novel features of con'struction and combination and arrangement of parts as will be more fully hereinafter described and pointed out in the claims.

Referring to the accompanying drawing:

Fig. 1 is a plan view of an electric circuit interrupter in the preferred embodiment of the present invention;

Fig. 2 is an enlarged top view partly in section of one of the contact assembly units shown in Fig. 1;

' Fig. 3 is an end view of Fig. 2 illustrating the 4 manner of attaching the lubricating device to the assembly unit;

Fig. 4 is an enlarged detail plan view of the attaching device per se; I

Fig. 5- isa modification of the attaching means for the lubricating device;

Fig. 6 is an end view of Fig. 5;

Fig. 'l is an end view of the cam for operating thecontact units; a I

Fig. 8 is a plan view thereof illustrating the arto give greater lift during 25 I fixedly together and the surface taken .on the line Q--9 blies II and. 5, which are attached to angled support members 8 and 9 respectively. The plate I is provided with grooves I 0 and i I respectively, within which snugly lit the two angled support members 8 and 9. The plate I is also provided with a centrally disposed opening I2 adapted to receive a shaft I3, upon which is mounted the four-lobed cam B.

Each. contact assembly disposed on opposite sides of the cam 6 has its various parts attached employed permit the parts of the assembly to be jointed together in a pivotless manner. The contact supporting member 8 is provided with a rigid arm I4 which extends laterally away from the inner face I5 of the supporting member 8. Permanently attached at the end of the rigid arm I4 is a contact I6 and mounted. in permanent alignment therewith so that their relationship cannot be changed is a second contact I1. The contact IT is permanently mounted on a flat leaf spring I8 at a point lying substantially on the longitudinal axis of said spring, the latter being supported at its other end by said supporting member 8. The inner end of said rigid arm I2 is provided with an opening I9 within which is disposed a fastening element 20 to which the leaf spring I8 heretofore mentioned is fastened. Molded to said rigid arm I 4 and projecting through said opening I9 on either side thereof is a spacer block 2| having a channel 22 formed on the upper side thereof within which the supported end of said leaf spring I8 is adapted to be snugly received.

The contacts I6 and I! are separated by means of a spring leaf timer arm 23 of spring material provided at its free end with a rubbing block or cam follower member 24,.which is in continuous engagement with the cam surface of the cam 6 as will be noted by referring to Fig. 1 and in intermittent engagement with the free end of the spring I8 for moving the movable contact I! away from the fixed contact I6 when the high points of the lobes of the rotating cam 8 are in contact with the follower.

The supported end of said timer arm 23 is adapted to be secured to the lower end of the fastening element 28 heretofore mentioned, a channel 25 being provided in the lower end of the molded spacer block 2| within which the supported end of said timer arm is adapted to be snugly received so that the timer arm together with the leaf spring I8 are maintained in permanent fixed alignment with the rigid arm I4.

As will be noted by referring to Fig. 3, the free end of the leaf spring 26 in lateral cross section is arcuate in shape with the center of the are lying within the leaf spring. It will also be noted that the upper or contacting surface 21 of the cam follower is flat so that in lifting the leaf spring to efiect a ribbonlike fiat springs plane of symmetry a-a of the QJMO, 10d

separation of the contacts I 6 and II, physical contact between the upper contacting surface 21 of the cam follower and the arcuate portion of the leaf spring will be made along a line only, all points of which will lie within the plane of symmetry w-c of the leaf spring. Even. though the upper contacting surface of the cam follower is made arcuate in shape and the outer free end of the leaf spring 28 is made flat, or both are made arcuate in shape with the arched portions disposed in opposing relationship, the same linear contact will be obtained without departing from the spirit of the invention. In this rnanner uneven wear of the cam follower will not impart any twisting action to the leaf spring, torsional stresses occurring therein will be thus avoided and a clean and instantaneous breakaway of the con-- tacts will be effected.

In the present illustrated case, the rubbing block. or cam follower 24 is made of an insulating material such as fiber, but when insulating material is not necessary other suitable materials may be used. The rubbing block is of such length as to provide a space 28 between it and the end of the spring I 8 when the rubbing block is in engagement with the low points of the lobes of the cam. Supported by the arm 23 and fixed adjacent the rubbing blocli 24 is provided a lubricating wick 29 made of felt or other suitable absorb ent materials, the lower edge 38 of which lies in substantially the same plane as the lower edge ill of the rubbing block so that there will be a physical contact or pressure between the wick and cam and such impact as may be imparted by the lobes of the cam will be taken up by the rubbing blocks.

In this manner a very thin film of oil will be continuously applied to the cam surface of the cam b.

As will be noted by referring to Figs. 2, 3 and 4 respectively the lubricating wick 29 is mounted on the rearward wall 32 of the cam follower by means of a sheet metal clip 33 fixed to the rubbing bloclr 21 by means of suitable rivets or the like 34. As will be noted the clip 33 is provided on its outer edges with serrated teeth 35 adapted to engage with the absorbent material in the manner illusl trated in Fig. 3 to substantially prevent any relative movement that may occur between the wicking and cam follower when the circuit breaker is operated at comparatively high speed.

In Figs. 5 and 6 are shown a modification of the lubricating wicking. In this modified form the wick 29 is first glued to the follower, thereby preventing substantially any relative movement between it and the cam follower. In addition to gluing the wick 29 to the cam follower, it is further secured to the same by means of a plurality of loops 36 and 31 of silk strands or other suitable strong absorbent material tightly wound around the upper and lower portions of the rubbing block and wick, tying these loops together sewing through the wick to the upper loops thereof, making several hitches to hold the loops together through the wicking. It will be further noted by reference to Fig. 6 that the lower loops are secured above and below the timer arm. In this manner such oil as may accumulate on the face of the cam follower or at the juncture of the holding portion 38 and follower 24 by the scraping action of its edge contacting with the cam 6, is prevented from flowing onto the follower and the contacts I8 and I 1 due to the fact that the flowing lubricant is readily absorbed by the silk fibers and transmitted to the wick by capillary action. This method of hitching around the loops and through the wicking has the additional contacting portion of the wicking is in all cases.

equal to or greater than the width of the working face of the cam 6. In this manner the cam follower and wicking being interposed between the cam 6 and the end portion of the leaf spring l8 acts as a bafile which prevents lubricant thrown from the cam in operating at high speed from fouling the contacts I6 and H.

The cam 6 heretofore mentioned is further provided with a plurality of grooves 39 on the low points of the lobes, the purpose of which is to prevent lubricant from accumulating on the forward wall 40 of the rubbing block by permitting spacer block having ing an a return flow of the lubricant to the wicking. The grooves, as will be noted by referring to Fig. 8, are staggered in relation to one another to distribute the wear evenly over the entire contacting surface of the cam.

In Fig. 10 is shown a modified form of the assembly units. In this modified form the cam follower 24 is mounted on the timer arm 23 intermediate the contacts l6 and I1 and their supported ends so as to give a greater lift during the make and break periods by increasing the effective leverage.-

While I have shown my invention as applied to the electric circuit breaker, it is not intended to limit myself to this type of device, nor do I intend to limit my invention to a liquid lubricant, since other types of lubricants may be used. Various devices are.provided with high speed movable cams that require lubricating which may be effected by the application of my invention by making various slight changes in the general form and arrangement of parts described without departing from the spirit of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an electric circuit breaker mechanism of the class described, a relatively stationary member carrying a contact, said memberhavlng an opening provided in the end thereof, a movable member carrying a cooperating contact supported by said stationary member, and a spacer block of insulating material molded to said stationary member and projecting through said opening to form an integral unit adapted for spacing and insulating said movable contact carrying member from said relatively stationary member.

2. In an electric circuit breaker mechanism of the class described, a relatively stationary member carrying a contact, said member having an opening provided in the end thereof, a movable member carrying a coperating contact supported by said stationary member, and a spacer block of insulating material molded to said stationary member and projecting through said opening to form an integral unit adapted for spacing and insulating said movable contact carrying member from said relatively stationary member, said a channel molded therein adapted to snugly receive the supported end of said movable member to maintain the contacts in positively fixed relation.

3. In an electric circuit breaker mechanism of the class described, a bracket having a relatively stationary arm carrying a contact, said arm havopening provided in the end thereof, a

fastening element disposed within said opening,

a movable arm carrying a cooperating contact positioned at the one end of said fastening element,

operative means for moving said movable contact arm positioned at the other end of said fastening element, and a spacer block of insulating material molded to said stationary member and extending through said opening to surround said fastening element, said spacer block being adapted for spacing said movable contactarm and operating means from said stationary member, channels provided in the upper and lower ends respectively of said spacer block, within which thesupported ends of said movable contact arm and operative means are adapted to snugly fit to maintain the parts in positively fixed relation.

4. In an electric circuit breaker mechanism of the class described, a movable arm carrying a contact, cam actuated means for moving said movable arm, an L-shaped supporting bracket therefor having a relatively stationary arm carrying a contact interposed between said movable arm and cam actuated means, a spacer block of insulating material molded to said stationary arm to form an integral unit therewith adapted for spacing and insulating said movable arm and cam actuated means from said stationary arm, and a single fastening element for securing the supported ends of said movable arm and cam actuated means to said stationary arm.

5. In an electric-circuit breaker mechanism of the class described, a bracket having a relatively stationary arm carrying a contact, said arm having an opening provided in the supported end thereof, a spacer block of insulating material molded to said stationary arm' and projecting through said opening, said spacer block being provided with a bore, a fastening elementinserted in said bore, a movable arm carrying a contact positioned at one end of said fastening element, cam actuated means for moving said movable arm positioned at the other end of said fastening element, said spacer block having a channel provided in the one end thereof adapted to snugly receive the fastened end of said movable arm therein to maintain its contact in positively fixed relation with the contact on said relatively stationary arm.

6. In an electric circuit breaker mechanism of the class described, a relatively stationary arm carrying a contact, a movable member carrying a cooperating contact and a cam actuated member adapted for contacting said first mentioned member to separate said contacts, one of said members having its contacting surface arcuate in shape, the center of which l es within the plane of symmetry of said movable member to thereby obtain line contact between said members, all points of said line lying within the plane of symmetry of said movable member.

'7. In an electric circuit breaker mechanism of the class described, a relatively stationary arm carrying a contact, a movable member carrying a cooperating contact, and a cam actuated member adapted to contact with the free end of said movable member and substantially at the midlongitudinal portion of said movable member to separate said contacts, one of said members having its contacting surface arcuate in shape, the center of which lies within the plane of symmetry of said movable member to thereby obtain line contact between said members, all points of said line lying within the plane of symmetry of said movable member.

8. In an electric circuit breaker mechanism of the class described, a relatively stationary arm carrying a contact, a movable member carryinga cooperating contact, means for effecting make and break action of said contacts including a cam actuated member adapted to bear against the free end portion of said movable member, one of said members having an arcuate surface for engaging the other member to make line contact therewith substantially along the longitudinal axis of said movable member.

9. In an electric circuit breaker mechanism of the class described, a relatively stationary arm carrying a contact, a movable arm of spring material carrying a cooperating contact in alignment with said first mentioned contact, said movable arm having its free end portion curved in cross-section, and means for eifecting make and break action of said contacts including a cam actuated member adapted to make line contact with said curved portion, all points of said line lying within the plane of symmetry of said movable member.

10. In an electric circuit breaker mechanism of the class described, a supporting member, a relatively stationary arm carried by said supporting member provided with a contact, a movable arm of spring material carried by said supporting member and carrying a cooperating contact in permanent alignment with said first mentioned contact, the free end portion of said movable arm being arcuate in cross section, and cam actuated member adapted to bear against the free end of said movable arm on a line lying substantially along the longitudinal axis of said movable arm to separate said contacts, said contacts being disposed intermediate of said cam actuated member and said supporting member.

11. In an electric circuit breaker mechanism of the class described, a supporting member, a relatively stationary arm carried by said supporting member and provided with a contact, a movable arm of spring material carrying a cooperating contact in alignment with said first mentioned contact, a leaf spring timer arm carried by said supporting member, and a cam actuated rubbing block on the free end of said timer arm adapted to bear against said movable arm on a line lying substantially along the longitudinal axis of said movable arm to separate said contacts.

12. In an electric circuit breaker mechanism of the class described, a relatively stationary member carrying a'contact, said member having an opening provided in the end thereof, a movable member carrying a cooperating contact supported by said stationary member, a spacer block of insulating material molded to said stationary member and projecting through said opening to form therewith an integral unit adapted for spacing and insulating said movable contact carrying member from said relatively stationary member, and cam actuated means adapted to contact with said movable member at its free end at a point to separate said contacts.

13. In an electric circuit breaker mechanism of the class described, a relatively stationary member carrying a contact, said member having an opening provided in the end thereof, a movable member carrying a cooperating contact supported by said stationary member, a spacer block of insulating material molded to said stationary member and projecting through said opening to form therewith anintegral unit..adapted for spacing and insulating said movable contact carrying member from said relatively stationary member, and cam actuated means carried by said relatively stationary member comprising a rubbing block adapted to contact with said movable member at its free end at a point lying substantially along the longitudinal axis of said movable arm.

14. In an electric circuit breaker mechanism of the class described, a. bracket having a relatively stationary arm carrying a contact, said arm hav ing an opening provided in the end thereof, a fastening element disposed within said opening, a movable arm carrying a cooperating contact positioned at the other end of said fastening element, and cam actuated means carried by said relatively stationary arm comprising a rubbing block adapted to contact with said movable arm at a point only to lift said movable arm and separate said contacts, said contacts being disposed between the point of lift and the supported end of said movable arm, the point of lift of said rubbing block lying substantially on the longitudinal axis of said movable arm and coincident with the center line of said contacts.

15. A unitary electric circuit breaker comprising in combination a pair of make and break contacts, means for supporting said contacts in positive alignment including a relatively stationary arm carrying one of said contacts, a leaf spring secured at its one endto said supporting means and having the other of said contacts mounted thereon, and means engageable with said leaf spring adjacent said contacts for separating said contacts, said last-mentioned means comprising a rubbing block the point of lift of which is maintained coincident with the center line of said contact to prevent torsional stresses occurring in said leaf spring during the make and break period of said contacts.

16. In an electric circuit breaker mechanism of the class described, in combination a pair of make and break contacts, means for supporting said contacts in permanently fixed relation, a leaf spring secured at its one end to said supporting means and having one of said contacts mounted thereon, a rotatable member having a cam surface, a rubbing block actuated by said rotatable cam member and engaging thefree end of said leaf spring adjacent its contact, and lubricating means carried by said rubbing block for continuously lubricating said cam surface, said last mentioned means being so constructed and arranged as to prevent lubricant thrown from said rotatable member from strikin said leaf spring.

17. In an electric circuit breaker mechanism of the class described, in combination a pair of make and break contacts, means for supporting I said contacts in permanently fixed relation, a leaf spring secured at its one end to said supporting means and having one of said contacts mounted thereon, a rotatable member having a cam surface, a rubbing block actuated by said rotatable cam member and engaging the free end of said leaf spring adjacent its contact, and lubricating means interposed between said rotatable member and the free end of said leaf spring and carried by said rubbing block for continuously lubricating said cam surface, said lubricating means being so positioned as to prevent lubricant from reaching said contact.

18. In an electric circuit breaker mechanism of the class described, in combination a pair of make and break contacts, means for supporting said contacts in permanently fixed relation, a leaf spring secured at its one end to said supporting means and having one of said contacts mounted face, a rubbing block actuated by said rotatable cam member and engaging the free end of said leaf spring adjacent its contact, and absorbent material carried by said rubbing block for lubricating said cam surface supporting means, said absorbent material being so constructed and arranged as to readily absorb lubricant thrown from said cam surface to maintain said contacts clean.

19. In an electric circuit breaker mechanism of the class described, in combination a pair of make and break contacts, means for supporting said contacts in permanently fixed relation, a leaf spring secured at its one end to said supporting means and having one of said contacts mounted thereon, a rotatable member having a cam surface, a rubbing block actuated by said rotatable cam member and engaging the free end of said leaf spring adjacent its contact, and absorbent material for lubricating said cam surface, supporting means for said absorbent material carried by said rubbing block, the contacting portion of said absorbent material being 'at least equal in width to the width of said cam surface to readily absorb any lubricant thrown therefrom by centrifugal action.

20. In an electric circuit breaker mechanism of the class described, in combination a pair of make and break contacts, means for supporting said contacts in permanently fixed relation, a leaf spring secured at its one end to said supporting means and having one of said contacts mounted thereon, a rotatable member having a cam surface, a rubbing block actuated by said rotatable cam member and engaging the free end of said leaf spring adjacent its contact, and absorbent material carried by said rubbing block, the contacting portion of said absorbent material being greater in width than the width of said cam surface to form a battle which readily absorbs lubricant thrown from said cam surface by centrifugal action.

21. In an electric circuit breaker mechanism of the class described, a supporting bracket including a relatively stationary arm carrying a contact, said supporting bracket being provided with an opening, insulation means disposed within said opening and secured to said bracket to prevent relative angular movement between said bracket and said insulation means, and a.

movable contact carrying arm secured at one end to said insulation means.

22. In an electric circuit breaker mechanism of the class described, a supporting bracket including a relatively stationary arm carrying a contact, said supporting bracket being provided with an opening, insulation means disposed within said opening and secured to said bracket to prevent relative angular movement between said bracket and said insulation means, said insulation means being formed with oppositely disposed parallel surfaces, a movable contact carrying arm secured at one end to the one surface of said insulation means and operative means for moving said movable contact carrying arm secured at one end to the opposite surface of said insulation means.

23. In an electric circuit breaker mechanism of the class described, a supporting bracket including a relatively stationary arm carrying a contact, said supporting bracket being provided with an opening, insulation means disposed within said opening and secured to said bracket to prevent relative angular movement between said bracket and said insulation means, said insulation means being formed with oppositely disposed parallel surfaces, a movable contact carrying arm secured at one end to the one surface of said insulation means and operative means for moving said movable contact carrying arm secured at one end to the opposite surface of said insulation means, said insulation means being provided with a recess on one of said surfaces adapted for receiving the supported end of said movable contact carrying arm therein to maintain the contacts on said stationary arm and movable arm in fixed relationship.

24. In an electric circuit breaker mechanism of the class described, a supporting bracket including a relatively stationary arm carrying ,a contact, said supporting bracket being provided with an opening, insulation means forming a spacer block disposed within said opening and fixedly secured to said bracket to prevent relative angular movement between said bracket and said insulation means, said insulation means being formed with oppositely disposed parallel surfaces, a movable contact carrying arm secured at one end to the one surface of said insulation means, operative means for moving said movable contact carrying arm secured at its one end to the opposite surface of said insulation means, the said. surfaces of said insulation means being provided with oppositely disposed recesses adapted to snugly receive the supported ends of said operative means and movable contact carrying arms therein to prevent relative lateral or angular movement between the supported ends of said movable contact carrying arm, said operative means and said stationary arm.

JOHN J. ROSE.

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