US1883873A - Ignition apparatus - Google Patents

Description

Oct. 25, 1932. l-LBREITBARI ET AL 1,883,873

IGNITION APPARATUS Filed Sept. 23, 1929 Patented j Oct. 25, 1932 UNITED- STATES PATENT OFFICE- HANS BREITIBART, ERWIN KURZ, AND WILHELM WALTHER, OF STUTTGABT, GERMANY, ASSIGNORS TO ROBERT BOSCH AKTIENGESELLSCHAFT, OF STUTTGART, GERMANY IGNITION APPARATUS Application filed September 23, 1929, Serial No. 394,688, and in Germany August 19, 1929.

and aims at allowing the rapid sparking mechanism such as a buzzer, starting magneto or the like which is often used to facilitate starting of an engine to operate only under conditions of retarded ignition. It has already" been proposed to cut out the make and break of a battery ignition system for i this purpose and at the same time to switch in a buzzer connected in series with a rotary switch coupled with the engine which permits current to flow to the buzzer only in retarded ignition positions of the engine. In this known arrangement the engine can only be allowed to run with retarded'ignition by either making the make and break adjustable to retarded ignition permanently working with starter ignition on retarded ignition. Such prolonged use of the starter ignition is however undesirable since for example buzz ers and plugs are rapidly worn out or since in hand-operated starter plugs the long turning becomes tedious and even impossible. The adjustment of the running ignition to retarded in the usual manner by rods or cables is also undesirable in aircraft since it is desirable to avoid weight, cost and the loss of space for the adjustment means.

These difficulties can be simply overcome by using an ignition system in which retarded ignition results in known manner by a second running make and break permanently at retarded ignition and by the starter ignition and all its switches being connected with the retarded ignition make and break.

'IWvo forms of construction of the invention are shown in the accompanying drawmg.

Figure 1 shows a battery ignition in which a buzzer is used for starting and v Figure 2 a battery ignition in which a hand-operated contact breaker is used for starting purposes.

In both cases an ignition coil is used which consists of a low tension coil 1 and a high tension coil 2. One end of the will is con-' nected to a battery 3 the other terminal of which is earthed. One end of the coil 2 is also earthed while the other end is con-.

nected with a rotating arm 4 of a high tensiondistributor, the high tension current flowing from the stationary contacts through the plugs to earth and back to the coil 2.

In Figure 1 the end of the coil 1 not connected to the battery 3 is led to the fulcrum 5 of the arm of a switch A, the free end of which can traverse three contacts 6, 7, 8. 6 is a free contact, 7 is connected to the insulated arm 9 of a contact breaker 9, 11 permanently set at advanced ignition. Contact breaker arms 9, 10 are moved by a rotating cam 13 which is coupled to the engine. The cam rotates in a clockwise direction so that, first the arm 9 is raised from the correspond ing contact 11 and then the arm 10- from its contact 12. The arm 10 is electrically connected to the contact 8 of the switch A, to which is also connected oneend of the winding 14 of an iron core 15, the other end being connected to the point of anchorage of a leaf spring 16. An iron block 17 is mounted on-the free end of the spring which also contacts with the point of an insulated contact screw 18. The latter is conductivelyconnected to a contact 19 of a switch B the arm of which is rotatable about a point 20 and is drawn towards a free contact 22 by a tension giving advanced ignition; if the arm of the switch A is on the contact 8, the contact breaker 10, 12 is switched into the circuit of the ignition coil 1 and gives retarded ignition.

If the switch A is placed on 8 and at the same time the arm of the switch B is held on the contact 19, part of the current through the coil 1 flows to earth through the winding- 14, contacts 16, 19 and the switch B in paral- V lel with that flowing to earth from 8 through.

contact breaker 10, 12. The spring 16 is thus set in rapid vibration in known manner by the cooperation of the iron core with the iron block 17 and the leaf spring 16 with the contact screw 19, as long as current'can flow from the battery 3, through the winding '1,'through 5, 8, the coil 14, the contacts 16,

18 and the switch B to earth and back to the battery. The circuit in the coil 1 is rapidly closed and opened by spring required for starting is caused in the plug ,tor.

which stant b the rotating arm 4 of the distribuhe spark produced in the plug by 'the vibrations of spring 16 serves to ignite the charge in the cylinder and start the engine. The sparkin produced by the vibrator augments the spar produced by the'make and break contacts 11--12.

As can be seen however sufiicient current can flow in the coil'14 to excite the automatic make and break device only so long as the to free contact 22.

lowing current to flow to the rapid sparking device. Rapid sparking with advanced ignition cannot therefore occur and accidents which couldbe caused thereby are consequently avoided. As soon as the engine has at tained running speed the switch B is released, and the spring 21 returns the switch blade In the example shown in Figure 2, a hand operated contact breaker is used instead of the electro-magnetic automatic type described with reference to Fi e 1. This consists of an arm 24 rocking a out the pivot 23, on the end of which is a contact 24a adapted to engage a cooperating contact 250: carried by an insulated contact screw 25.

A projection 26 of insulating material is provided on the arm 24 and slides on a cam 27 mounted on a spindle 28. The latter may be turned by a hand crank 29 and is mounted in bearings 30, 30 so that it can be displaced axially by pressure on pin 31 of insulating material is inserted in the end of the spindle 28 away from the hand crank. the end of which bears against the free end of a leaf spring 33 mounted at the other end on an insulating block 32. The spring 33 carries, on the side remote from the insulating p' I 31, a contact 34 which is opposite a stationary earthed contact 35.- Contacts 34:

and 35 are normally held apart by spring 33.

The arm 24 is conductively connected to a. contact 36 of a double rotary switch C. The arm of the switch C passing over the contact these vibrations of the 16 and the rapid succession of sparks happensto be switched in at that in be switched-in parallel to the first for rethe hand crank. A'

36 rotates switch C turns about an axis 39 and can rest on a contact or on a free contact41. The two pivotal axes'37 and 39am conductively connected to one another and also to theinsulated arm 9 of the advanced ignition contact breaker 9, 11. The contact 36 is also connected with the insulated arm 10 of the retardedignition contact breaker 10, I2 and the contact 40 with one end of thelow tension coil 1. j Y

In the position shown, current can flow. from the batte 3, through the coil 1 to the pivot 39 and t ence through the advanced ignition contact breaker 9, 11 and earth back to the battery; the retarded i 'tion contact breaker 10, 12 is also switche -inj parallel to the advanced ignition contactbreaker be tween the pivot 39 and earth throu pivot 37 and the contact 36. W ith bot con -v tact breakers switched-in together, the double breaker thus formed only gives retarded'ignition since the secondcontact breaker 10 '12 is closed when the first opens-'andthere ore the opening of the second contactbreaker determines the'timing of the ignition.

The usual duration of closure of the running contact breaker extends over a larger angle of rotation than'the angle of adjustmentbetween advanced and retarded igmtion and therefore this exceeding of the closure period of the two contact breakers usually occurs so that'the second contact breaker can tarded ignition in almost-all cases. I

The leaf spring 33 of the hand operated contact breaker 2 4, 25 for the starting ignition is so tensioned that-it tends to movethe spindle 28 to the left and separate the two. contacts 34, 35. If however on turning the crank a pressure is exerted on these simultaneously in the direction of the arrow, the spindle 28 is moved to the right into the position shown in which the insulating end 31 of the spindle bends back the spring33 andforces the contact 34, 35 together. The circuit of the contact breaker for the starting ignition is thereby switched-in parallel to the retarded ignition contact breaker from 25, 33, 34, 35 to earth. This branch can'be rapidly opened and closed by turning the crank 29 and with it the primary circuit of the ignition coil is opened and closed as long as the twocontact breakers 9, 11, and 10, 12 are open, i. e. on retarded ignition. If the retarded ignition contact breaker is cut out by the arm resting on the contact 36 bein moved to the free contact 38 and the advanced ignition contactv breaker is alone in circuit; the starting ignition is cut out similarly as in the preceding example. The branch circuit of the startlng ignition is also automaticall about an axis 37 and can also rest on a free contact 38. The second arm of the hthe 36 through 24,

combined with the switch A in one housing similarl as the .two switches of the double switch (l in the second exam le.

The buzzer 14, 15, 16, 17, 19 or the hand contact breaker 23-25 can also be located in ando the switeh housing so that all the mechanism forswitching over from advanced to retarded ignition and for switching on and operating sta igmition are combined at one point y require connecting up with the other parts of the ignition apparatus by cable leads. We claim: 1. Ignition apparatus for internal combustion engines-comprising a primary coil, a

source of current in series with said coil, a mechanically operated contact breaker permanently setat advanced ignition adapted to be connected in circuit with said primary coil, a mechanically operated contact breaker permanently set at retarded ignition also adapted to be connectedin circuit with said primary coil and rapid sparking means con-- nected in parallel w:th said retarded contact sourceof current source of current in series breaker.

2. Ignition apparatus for internal combustion enginescomprising. a primary coil, a in series with said coil, two mechanically operated contact breakers permanently setto open at different instants, se-

lective switch means for operatively assopne'of said contact breakers wlth said primary coil and rapid sparking means connected in;pa'rallel with the contact breaker which opens latest.

I 3. Ignition apparatus for internal combustion engines comprising a primary coil, a

mechanically operated contact, breakers permanently set to open at difi'erent instants,

selective switch means for operatively associating oneof said contact breakers with said primary coil, earth connections for said prirapidsparking means connected in parallel with the contact breaker which opens latest and an earth connection for said rapid sparking means.

4. Ignition apparatus for internal combustion engines comprising a primary coil, a source'rofcurrent in series with said coil, two mechanically operated contact breakers permanently set to open at difierent instants, selective switch means for operatively m0- ciating one of said contact breakers with said primary coil, earth connections mary coil and contact breakers, rapid sparkmg means connected in parallel with the contact breaker which opens latest, an earth connection for said rapid sparking means and switch means between said earth connection and rapid sparking means- 5. Ignition apparatus for internal combustion engines comprising a primary coil, a source of current in series with said coil, two

mechanically operated contact breakers permanently set to open at different instants, se-

with said coil, two

for said pri-- olperatively associating one of said contact primary coil and electro-magnetically operated rapid sparking means connected in parilllel with the contact breaker which opens atest. a

6. Ignition apparatus for internal combustion "engines comprising a primary coil, a source of current in series with said coil, two mechanicallyoperated contact breakers permanently set to open at difierent' instants, selective means for operatively associating one of said contact breakers with said primary coil and a buzzer connected in parilllel. with the contact breaker which opens atest.

7, Ignition apparatus for internal combus tion engines comprising a primary coil, a 'source of current in series with said coil, two mechanically operated contact breakers permanently set to open at different instants, 'selective switch means for operatively associating one of saidcontact breakers mary coil and manually operated rapid sparking means connected in parallel with the contact breaker which opens latest.

In testimony whereof we. have hereunto afiixd our signatures.

HANS BREITBART. ERWIN KURZ. WILHELM WALTHER.

with said priill

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