US1050799A

US1050799A - Igniter for gas-engines.

Info

Publication number: US1050799A
Application number: US55201310A
Authority: US
Inventors: Stephen F Briggs
Original assignee: Briggs and Stratton Corp
Current assignee: Briggs and Stratton Corp
Priority date: 1910-03-28
Filing date: 1910-03-28
Publication date: 1913-01-21
Anticipated expiration: 1930-01-21

Description

I S. I. BRIGGS.

IGNITER FOB. GAS ENGINES.

APPLIOATION FILED MAR. 28, 1910. 1,050,799, Patented Jan.21,1913.

3 SHEETSSHEET 1.

S. F. BRIGGS.

IGNITEE FOR GAS ENGINES.

I APPLIOATION FILED MAR. 28, 1910. I 1,050,799. Patented Jan.21,1913.

3 SHEETS-SHEET 2.

s. 1". BRIGGS.

IGNITER FOR GAS ENGINES.

APPLICATION FILED MAR. 28, 1910.

1,050,799; Patented Jan. 21, 1913.

3 SHEETS-SHEET 3.

UNITED STATES PAEENT oFFIoE.

STEPHEN BRIGGS, on MILWAUKEE, WIscONsIN, AssIeNoR T0 BRIGGS & sTRATToN- COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

IGNITEB FOR GAS-ENGINES.

Specification of Letters Patent.

Patented Jan. 21, 1913.

Applicationffiled March 28, 1910. Serial No. 552,013. I

To all whom it may cancer it Be it known that 'I, STEPHEN R'Bnloos,w

vented new and useful Improvements in.

Igniters for Gas-Engines, of which the fol lowing is a description, reference being bad to the accompanyingdrawings, which are a part of this specification.

This invention has for its object to provide an igniter' of the induction coil type with a switch for the primary circuit which will be closed mechanically by the operation of the engine and will be opened electrically by means depending upon the closing of the switch, thus producing a closed circuit of momentary duration and independent of the speed of the engine and also obviating the possibility of'the circuit remalning closed when the engine stops.

Another object is to utilize the magnetic elfect of the induction coil itself to eflect the opening of the primarycircuit switch.

Another object'of theinvention Is to improve upon details of construct-Ion of igniters of this type.

In the accompanying drawings I show an exemplifying structure embodying the invention, but it is to be understood that the invention is capable of embodiment in dif-- ferent forms.

WVit-h the above and other'objects in View the invention consists in the construction or relative arrangement ofcertain parts and in combinations thereo-fas pointed out in the claims.

. Referring to the drawings: Figure 1 is asectional View of an igniter embodying the present invention, the cam being magnetically withdrawn from engagement withthe movable switch contact to break the primary circuit; Fig. 2 is a plan view thereof with the cap removed, showing the switch contacts in their closed position; Fig. 3 is a similar view with the switch contacts magnetically released; Fig. 4 is a detail sectional view showing the construction of the cam parts and the relation of the cam to the movable switch contact at the time of closing the primary circuit; Fig. 5 is a detail perspective view of the cam arts and their casing, the latter being sectioned; and, Figs. 6 to 11 are diagrams of modifications of this invention.

In these drawings 10 indicates a casing which is intended to be rigidly connected to the engine base or other suitable support and has a distributor block 11 of insulating material fitting in its upper end. A rotor is j ournaled within the casing and contains the spark coil in an insulating cyindrical shell 12, said spark coil. comprising the core 13, the primary winding 14 and the secondary winding 15.

The lower journal mounting for the rotor consists of a metal plate 16 secured to the insulating shell 12 and carrying a trunnion 17 which is journaled in a ball bearing 18 at the bottom of the casing 10 and is intended for connection with the cam shaft of the engine. The upper journal mounting for therotor comprises a tubular trunnion 19 mounted on the upper end of the insulating shell 12 of the rotor, preferably by having annular flanges 20 molded into the hard rubber or other insulating composition of which said shell is made, said trunnion 19 being journaled in a ball bearing 21, threaded in a flanged bushing 22, which in turn is threaded into the distributing block 11.

An annular plate 23 is mounted to turn on top of the distributer block 11 by fitting around the flange of the bushing 22, this movement being accomplished by means of an arm 24 projecting radially from the plate 23 and adapted for connection with the spark advancing and retarding mechanism of the engine,'and being limited by screw stops 25 projecting from the distributer block and rlding in arc'shaped slots 26 of the plate 23. The plate 23 has mounted on it the switch contacts which control the primary circuit of the induction coil, the stationary contact 27 being insulated from the plate 23 and having a screw contact point 28 for adjustment, and't-he movable contact 29 being pivot-ally mounted on a post or stud 3O projecting from the plate 23 with a leaf spring contact point 31 to engage the screw contact point 28 and a curved finger 32 to be engaged by the cam of the rotor for closing the contacts and a spring 33 for retracting the movable cont-act when it is disengaged from the cam,

The cam carried by the rotor for engaging the contacts is one which is under the influence of the magnetic attraction of the core 13 of the spark coil so as to be automatically withdrawn from its operative position immediately upon effecting the en gagement of the contacts. This cam may be .variously constructed and arranged, but preferably comprises a cam member 34 clamped upon a stem 35 between a shoulder thereof and a spacing collar 36 by means of a nut 37 threaded on the end of the stem, said cam member being provided with as many equally spaced radially projecting cam lugs 38 as there are cylinders to the engine. The lugs 38 pass out through slots 39 in the upper end of the tubular trunnion or cam cas ng '19 and are slidable verticallytherein to occupy a position in the same plane as. the finger 32 of the movable contact, so as to engage therewith during the rotation of the rotor,-or to occupy -'a position below said plane where they will escape the finger 32. The stem'35 is normally held in its upper position with spring pressure with the cam lugs 38 in-the plane of the finger 32 of the movable contact by means of a lightcoil spring 40 surrounding the stem and bearing at its upper end against the cam member '34 and at its lower end against a, cup shaped spring seat 41 which also surrounds the stem 35 and which'has ears 42 at its upper edge bent outwardly to engage the lower ends of the slots 39. The lower end of the stem 35 is preferably enlarged to of the tubular trunnion 19, so as to avoid I the formation of a dash pot that would tend to retard its motion, or it may be provided with a vent opening 44 therethrough having the same effect. The end of the downward stroke of the cam stem is-cushioned by providing a disk of cork or leather or other suitable ielding material 45 in the bottom of the tu ular trunnion 19, and the upward movement of the cam stem is limited and cushioned by its upper end striking against a similar disk 46 contained within a screw cap 47 which is threaded on the upper on of the tubular trunnion.

A metal shell 48 forms a cover ting upon a stud 49 standing up from the plate 23 and a stud 50 standing up from the insulated stationary contact\27, the'latter being protected from contact with the cover by means of an insulated bushing 51.sur-

rounding it. The stud 49 has a nut 52 threaded thereon and the stud 50 has a nut 53 threaded on it to clamp the cover in for the contact mechanism and is held in place by fitplace and to form binding posts for the terminals 54 ofthe condenser 55 which is contained in the space between the rotor and the casing 10.

One end of the primary winding is connected with one end of the secondary winding, as usual, at 56 and is grounded on the frame by connecting with the metal plate 16 of the lower trunnion, there being a spring brush 57 on the casing 10 and bearing against the plate 16 to insure a perfect I contact for this The other end 0 the primary winding is connected at 58 with the tubular trunnion 19 which is in metallic engagement through the bearing and otherwise with the parts forming the casing for the contact mechanism, including the plate 23 and the movable contact 29. Thus it will be seen, that when one terminal, 75, of the battery 76 is grounded on the frame, as usual, and thereby is in connection with the grounded end of the primary coil, and the other terminal 77 of the'battery 'is connected with' the binding post formed by nut 53, the primary circuit will be closed through the primary windin of the induction coil upon the contact points 31 and 28 becoming engaged and will be broken upon their separation. While one .end of'the secondary winding 15 of the induction,coil is grounded on the frame of the engine'through the connection of the casing 10 therewith, as previously described, the other. endthereof is connected at 59 with a tubular sleeve 60 near the upper end of 'the cylindrical shell 12 of the rotor, which sleeve contains a spring pressed distributer brush 61, sweeping around the interior of the distributer block 11 and coming into engagement .with distributor segments 62 embedded in said distributer block. These segments 62 are connected by lead wires 63 with tubular sockets 64 embedded in the ,sideof the distributor block and which are adapted for connection with the plugs of the usual high tension leads 78 which connect with the spark plugs 79 of the several cylindersof the. engine. There being one of,the contact segments 62 for each cylinder of the engine, it is obvious that at the time of the operation of the switch contacts by means of the cam, the secondary current from the induction coil will traverse thespark'plug connection leadin from whichever contact segment 62 the usb 61 then engages. Thus the secondary circuit of the induction coil constitutes an ignition means by which ignition is der of the enginew ich has its piston in position for the explosion.

In operation, instead of the cam operating upon the movable contact to effect the closing of the primary circuit ,a variable length of time, depending upon the speed of movement of the cam, as would be done produced in that cylinround frame connection.

if the cam remained fixed'with relation to the rotor, said cam, immediately upon closlng the primary circuit, is drawn downs wardly by the attraction of the induction coil upon the head 43, and is thus moved out of the plane of-engagement with the movable contact 30, so as to permit said contact to beretracted by its spring 33 and break the primary circuit. The period of contact at slow speed is therefore muchreduced from what it would be if the cam were not moved out of its operative relation with the movable contact immediately...

lug 38 still beneath the finger 32 of the mov-' able contact so that the cam does not rise to its normal position under the influence of its spring 40 until such cam lug has moved sufliciently to free it from the finger,

when the spring returns the cam to itsup-- er position ready .to engage the contacts y means'of the next cam lug. It is pose sible that when theengine is operated at an exceedingly high speed the instantaneous period of engagement of the cam lugs 38 with the movable contact will be of such short durationthat the magnetic effect will be insufiicient to draw the cam from its normal upper position before the 'cam lug passes the finger, but this is an advantage rather than a disadvantage, for at such times it is desirable to have the periodpf contact relatively longer than at slow speeds.

Besides effecting a contact of uniform and momentary duration atdifierent speeds of the engine, the present inventionavoids the possibility of the engine being brought to a stop in a position in which it will leave the primary circuit closed, for should the engine be stopped with the parts in the position shown in Fig. 2, the closed primary circuit would cause the'attraction of the cam by the core of the induction coil so as to withdraw said cam from. its engagement with the movable contact and thereby permit the contact tomove away,from the stationary .contact under the influence of its spring to open the primary circuit, and the parts would remain in this position until the engine is again started.

It is .obvious that this invention is not limited to the specific means shown for utilizing the magnetic influence of the in- .duction coil for breaking the primary circuit after it has been closed by mechanical means, or to the magnetic influence being that of the induction coil, but that various other means may be employed for accomplishing the object sought without departmg from this invention and other electrothe cam .to break the circuit. means on the cam or the armaturemay be provided to prevent vibration. The inducmagnetic means in the primary circuit may be employed for magnetically breaking the circuit which 1s mechanically closed. I

therefore desire it to be understood'that this invention is not limited to any specific form or arrangement of parts except 111 so faras such limitations are specified in theclaiins.

As illustrating in diagram some of the various modifications comprehended by this invention and included within the terms of the claims reference is. made to Figs. 6 to 9-:

inclusive.

In Fig. 6 an engine operated cam engages an armature81 of the magnet 82 and thereby closes the magnet 'circuit, whereupon the magnet becomes energized and attracts. the armature and moves it away from Insulating tion coil may be omitted in this form, the

cam and armature constituting a make and break -device located in the cylinder, or an induction coil may be provided with its primary circuit controlled by (the engagement' of the cam and thearmature, eitherby; including the primary winding in the magnet circuit shown .or in'anothercircuit in a manner similar to the connection Illustrated in Fig. 7.

In Fig. 7 the cam 83'engages a contact 84 and moves it.into'engagement with the armature 85 of magnet 86, thus closing the magnet circuit 87 and also thetprimary circuit 88 of an induction coil 89. With this construction also, the-,ignition contact is made mechanically and is broken electrically through a circuit established by the primary switch contacts. In-such construction the batteries for the magnet circuit and the primary circuit of the induction coil maybe connected in'multiple as shown.

Fig. 8 represents substantially the same system as shown in Fig; 7 with the magnet 86 contained in the primary circuit 88 of the induct-ion coil 89, the operation remaining the same. y

Fig. 9 more closely resemblesin diagram the preferred construction illustrated in Figs l to 5, wherein the ma et 86 of the system shown in Fig. 8 consists of the induction coil 89.

In Fig. 10 the rotor trunnion 92 is provided with as many flat surfaces 93 as there are cylinders to the engine and a spring actuated contact 94 bearing on the trunnion is permitted by these fiat surfaces 93 to move its contact point into engagement with a stationary contact point 95 to close the primary circuit 96 of the induction coil 97 the core thereof constituting the trunnion 92 of the rotor, though shown separate in the diagram for clearness of illustration. A bell crank lever 98 stands close to the trunnion '92 and constitutes the armature for the on the insulating attracted to the trunnion 92 when the primary circuit is closed. In moving toward the trunnion 92 it swings its upper end against a cam 99 on the contact 9& which effects the disengagement of the contacts to open the primary circuit, and then the bell crank armature 98 returns to its normal position, preferably through the action of the fiat surfaces 93 of the trunnion 92 thereon,

In Fig. 11 a modification of the construc-. tion of the cam .end of the 'rotoris illus-v trated, wherein a trunnion 100'is mounted shell 101 of the induction coil and has the cam stem 102 slidably mounted in it with thehead 103 forming the armature for the ma et and contained within. the endof the pr1mary winding-104: of the induction coil sothat saidprimary winding acts upon it as a solenoid to give a greater magnetic efiect than when the attraction of the core 105-is alone relied upon. The movements of the armature stem are cushioned as before, and the cam 106 issecured to the end of the stem 102 by means of a nut 107, .the spring 108 being confined withinannular grooves in the end of the trunnion 100 and the bottom face of the cam 106 respectively. The cam is prevented from turning by having a pin 109 passing 'throu h an opening therein, said pin being threa ed in the trunnion 100 and being bent I over to the axis of the rotor where it is providedwith a lug 110 engaged by a contact spring 111 on the cover 112 for maintaining electrical connection therewith. With this I form of the invention a greatermagnetic efgaging the feet is accomplished and less resistance is imposed upon the movements of the cam.

What I claim as new and desire to secure by Letters Patent is- 1. An igniter for gas engines, comprising switch contacts, engine drlven means engaging the switch contacts with each other at intervals, an electro magnet for disenswitch contacts controlled by the engagement of said switch contacts and an ignition circuit including the switch contacts and controlled thereby.

2. An igniterfor gas engines, comprising switch contacts, an engine dr ven cam engaging the switch contacts with each other at intervals, an electro magnet for disengaging the switch contacts controlled by the engagement of said contacts, and an ignition circuit including the switch contacts and controlled thereby.

3. An igniter for gas engines, comprising switch contacts, engine driven means for closing the switch contacts, an. electro magnet for disengaging the switch contacts controlled by the engagement of said contacts, said electro magnet constituting an induction coil, and a spark plug connected with the secondary circuit of the induction coil.

4. An igniter for gas engines, comprising switchcontacts, an engine driven cam normally in position for engaging and closing the ,switch contacts at intervals but movable from said position, an electro magnet energized by the closing of the switch contacts and adapted to withdraw the cam from its operative relation with the switch contacts and thereby cause theopening of the switch contacts, and ignition means controlled by the closing of the switch contacts.

5. An igniter for gas engines, comprising switch contacts, an englne' driven cam normally in position for engaging and closing the switch cont-acts at-intervals but movable from said position, and an induction coil having its secondary circuit forming an ignition means and its primaTy circuit controlled by the switch contacts, said in-' duction coil constituting a magnet for withdrawing the cam from its operative position with relation to the switch contacts to cause the opening of the switch contacts.

6. An igniter for gas engines, comprising a swiitch contact, an induction coil rotatably mounted and adapted to be connected with the engine to be driven thereby, and a cam carried by the induction coil in position to normally engage and close the switch contact but movable from said position, the primary circuit of the induction coil being controlled by the switch contact, said induction coil constituting a magnet to be energized by the closing of the switch contact and adapted to withdraw the cam from its operative relation with the switch contact, the secondary circuit of the induction coil constituting an ignition means. 7. An igniter for gas engines, comprising a rotatablymounted induction coil adapted to be driven by the engine, a cam carried by the induction coil, a switch contact engaged by the cam for closing the primary circuit of the induction coil, and movable means attracted by the. induction coil when it is energized for disengaging the cam and the contact for breaking the primary circuit, the secondary circuit of the induction coil constitutingan ignition means.

8. An igniter for gas engines, comprising I of the induction coil when the induction coil is energized by the closing of the rimary circuit for withdrawing the cam From its engagement with the switch contact and thereby opening the primary circuit, the secondary circuit of the induction coil constituting an ignition means.

9. An igniter for gas engines, comprising a rotatably mounted induction coil adapted to be driven'by the engine, a cam slidably mounted on the induction coil and turning therewith, a spring for holding the cam in a normal position, a switch contact in position to be en agedby the cam when the cam is in its'normal position and adapted to be swung thereby, a stationary switch contact to be engaged by the swinging contact, said switch contacts being included in the primary circuit of the induction coil for closing the same, and an armature attracted by the magnet formed by the core of the induc tion coil, and connected with the cam for moving the cam out of its engagement with the swinging switch contact and thereby causing the interruption of the primary circuit, the secondary circuit of the induction coil constituting an ignition means.

10. An igniter for gas engines, comprising an engine driven rotor-mounted on trun nions, one of saidtrunnions being tubular, a cam mounted to slide in said tubular trunnion and having cam lugs projecting through slots in, the tubular trunnion, a stem connected with the cam, a cup contained within the tubular trunnion and having outwardly bent ears engaging the slots of the trunnion, a spring seated in the cupand bearing on the cam for holding the cam in a normal position, a cap mounted on the end of the trunnion for limiting the movement of the cam and determining the normal position thereof, a head on the stem forming an armature, an induction coil contained within the rotor and forming a magnet for attracting the armature and thereby withdrawing the cam from its normal posi-- tion, and a switch contact for controlling the primary circuit of the induction coil mounted in a position to be engaged by the cam lugs in the normal position of the cam and to be released thereby when the cam is moved by the attraction of the magnet for opening the primary circuit of the induction coil, the secondary circuit of the induction coil constituting an ignition means.

11. An igniter forgas engines, comprising an engine driven rotor, trunnions on which the rotor is mounted, a cam movably mounted on one of the trunnions, an induction coil carried by the rotor and constituting a magnet for moving the cam out of its normal position, a movably mounted plate, a switch contact carried thereby for controlling the primary circuit of the induction coil and adapted to be engaged by the cam when the cam is in its normal position for closing the primary circuit, said cam being'released from the switch contact by the attraction of the magnet, the secondary circuit of the induction coil con stituting an ignition means, and means for moving the plate for advancing or retarding ignition.

12. An igniter for gas engines, comprising a casing, a rotor journaled within the casing, an induction coil contained within the rotor, a cam carried by the rotor, switch contacts for controlling the primary circuit of the induction coil operated by the cam, a distributing block surrounding one end of the rotor, contact segments carried by the distributing block adapted for connection with the spark plugs of the respective cylinders of the engine, a brush carried by the rotor and connected with the secondary coil of the induction coil and adapted to engage the contact segments, and a condenser contained in the space between the rotor and the casing and connected with the switch contacts.

"13. An igniter for gas engines, comprising a casing, a rotor journaled within the casing, an induction coil contained within the rotor, a cam carried by the rotor, switch contacts for controlling the primary circuit of the induction coil operated by the cam, a distributing block surrounding one end of the rotor, contact segments carried by the distributing block adapted for conmotion with the spark plugs of the respective cylinders of the engine, a brush carried by the rotor and connected with the secondary coil of the induction coil and adapted to engage the contact segments, a condenser contained in the space between the'rotor and the casing and connected with the switch contacts, and a plate adjustably mounted 011 the distributer block for carrying the switch contacts and adapted to be moved for advancing or retarding the ignition.

In testimony whereof, I afiix my signature, in presence oftwo witnesses.

A. L. MORSELL, C. H. KEENEY.