US1733940A - Ignition timer - Google Patents

Description

Oct. 29, 1929.

W. A. CHRYST IGNITION TIMER Filed Jan. 13. 1928 Patented Oct. 29, 1929 UNITED STATS Panam?v OFFICE WILLIAM A. CHRYST, F DAYTON, OHIO, ASSIGNOR TO DELCO-REMY CORPORATION,

' OF DAYTON, OHIO, A CORPORATION OF DELAWARE IGNITION TIMER Application led January 13, 1928. Serial No. 246,637.

This invention relates to ignition apparatus for internal combustion engines, and more particularly to the control of ignition timing in response to variations in engine speed and to variations in engine load.

One object of the present invention is to provide for the control of ignition timing by means cooperating with an annular piston sliding within an annular cylinder provided by the timer housing and located concentric with the axis of the timer driving shaft, the piston and cylinder cooperating to provide a suction chamber which is connected with the engine intake passage. In carrying out this obj ect of the invention, I provide a cam carrying shaft which is journalled upon a portion of the timer driving ,shaft so that it may be rotated relative thereto, and I connect the vshafts by a mechanism which can be confined within the timer housing and which is con'- trolled by the suction operated piston referred to. A collar which is connected with the piston and moves axially of the two shafts is so connected with them as to vary the angular l relation between these shafts in `response to movements of the piston.

Further objects and advantages of the present invention will be apparent from the following description, reference bein had to the accompanying drawings, wherein a preferred form of embodiment of the present invention is `clearly shown. In the drawings: .t Y

Fig. 1 is in part a vertical sectional view of an ignition timer embodying the present invention and in part a diagram showing the manner of connecting the suction chamber of the ignition timer with the engine intake passage. U

Fig. 2 is a plan view of the timer with the distributor head removed, and is a view on the plane of the line 2-2 of Figfl..

Fig. 3 is a fragmentary sectional view lookin in the direction of the arrow 3 of Fig. 1. Fig. 4 is a view similar to Fig. 1 showing certain parts in other operating positions.

Fig. 5' is a sectional view on the l1ne ,5 5 of Fig. 1.

In the drawings, 20 designates the housing of the timer whlch supports a conventional socket 22 having a contact 23'for en aging a contact 24 supported by a rotor connected with the contact 24 and rotated adjacent to a plurality of distributor'posts whichfare arranged in af circular row. One of these posts is shown at 27 and is integral with a socket 28 for receiving a plug or terminal connector (not shown) attached to a wire leading to an engine spark plug.

The rotor block is supported by and driven by a cam carrying 'shaft 30 which rotates loosely about an extension 31 of a timer driv. ing shaft 32 which is supported by a bearing provided by the tubular shank 33 of the timer housing. The shaft '30 is provided with a cam 34 which co-operates with a rubbing block 35 of a circuit breaker lever 36 carrying a contact 37 adapted to engage a stationary contact 38 supported by an adjustable bracket 39 which is adjustable about the pivot stud 40 of the lever 36. A leaf spring 41 conducts current from a terminal 42 to the lever 36 and urges the contact 37 toward the contact 38 and the rubbing block 35 toward the cam 34. The lever 36, bracket 39 and terminal 42 are supported by a plate 43 having ears 44 by which the late may be attached to the timer housing y screws 45. The terminal bracket 42 is insulatingly supported by the plate 43 and is connected with a terminal screw 46 which is insulated from the housing. A condenser which is contained within a case 47 is attached by clip 48 and screw 49 -to the plate 43. One

-of the con denser foils is electrically; connected with the condenser case 47 and hence with the plate-43, and the other foil is connected with the terminal bracket 42 by a conductor 50.

The lower end of the cam carrying shaft 30 rests upon a shoulder 5'1 provided by the shaft 32 and is attached to afplate providing arms 52 each of which is adaptedto cooperate with an arm 53 of a weight 54. Each weight 54 is supported by weight plate 55 and swings around a stud 56 attached to the plate 55. A spring 57 connects a stud 58 carried by an arm 52 -with one of the studs 56 and in this way tends to move the plate 54 toward the shaft 32. .The plate 55 is attached to and is t lock 25 v carrylng a distributor segment 26 electrically i Awhich is supported by a vdiagrammatically by a carburetor 61 and an intake manifold 62.- The throttle 63 of the carburetor 61 is operated by Aa lever- 64 and a rod 65. The carburetor is provided with a passage 66 which is anterior to the throttle when closed and which is on the engine side of the throttle when thev throttle is opened a substantial'amount. The passage 66 is con# nected by a pipe 67 with an elbow 68 screwed into the timer housing 20 and communicates with an annular cylinder or suction chamber 70 having a movable wall provided bypiston 71 which slides along an annular boss 72 pro- 'viding a part of the bearing for the shaft 78 res spective y space between the flanges l 32. The cylindrical surfaces defining the annular cylinder 7 0 are en piston packing'member 3 which is attached l rivets 74 .to the piston, andl these rivets 74 g a so secure tothe piston the flanges and 76 of two nested cup-shaped tivelyv which' are `located concentric with t e shaft 32 and which are provided with inwardl `extending flanges .79 'and 80 y relocated m spaced relation.l The 79` andl 80 is'occupied by a disc or` collar 86, the ,thickness of, which is slightly less than the distance between the flanges 79 and 80 so that the collar aged by an annular- 86 is Vfree to 'rotate relative to the piston 71.v

. The collar 86 isprovided with inwardl tending lugs 8 whichy are -receive by longitudinally extending grooves 88 provided in the shaft 32. and oblique slots 89 in the intermediate shaft 59. Normally'a spring 90 urges the piston 71 upwardlyI until the flange 476 of the part 78 strikes an annularplate 91 attached b screws 92 to the housing 20.

The sha 32 is driven by the engine in the usual manner and `drives the intermediatel shaft 59 throughthe lugs 87 of the collar 86. The intermediate shaft 594drives thecam 3 4 through the cooperating weights 54 and lever ,arms 5 2. As the speed of the shaftincreases,

the weights 54 move outwardly due `to centrifl force and move the cam clockwise re ative to the shaft 32 in order to advance the timing'of. the ignition, the normal direction y of rotation' of the' cam 34 being clockwise.l

In .this vway the spark is advanced auto- P matically as the s d of the en e increases.. While the engine is idling, t e throttle 63 'will be opened only a slight amount and thev passage 66 will be practically cut off from thev influence of suction in the. intake manifold 62. Therefore the sprin will befree to maintain the collar 86 in t e position shown in 1 and the timing of the ignition will be I wise as cumulativelyand differentially. of the engine increases, both devices may act .creased while itsload is bein lopened (to permit the lengine to -increase -its "speed,

the passage ,66 will be placed in comjthe engine intake so that the pressure in the suction chamber 70 will be ysub-atmospheric. l Therefore the piston 71 will bemoved downwardly to move the collar 86 downwardly. The oblique slots 89 are so constructed rthat downward movement of the munication. with collar 86 will cause the shaft 59 to move clockviewed fronrthe top'of the ignition timer. Therefore, the cam 34 will'be rotated clockwise'relative to-the'shaft 32 and the timing of the ignition will be advanced.

When the engine load is suddenly increased, Itending to reduceits speed, and the throttle 63 is opened to supply a greater lamount of fuel to the engine, the suction in-.the intake 62 will be reduced; consequently the spring 90 will move the piston 71 upwardly to a position in which equilibrium is established between the spring pressure and the pressure diferential tending to move the piston down-- wardly. Consequentlythe collar 86 will be moved upwardly a certain amount in order to retard lthe ignition in amount corresponding to the load of the engine.

It is apparent that the speed responsive centrifugal 'device and the suctionfresponsive device' for controlling the advancing and retarding of vthe timing ignition may operate Asthe speed cumulatively to rotatethe cam 34 relative to the shaft'32 in such direction as :to advance the timingv of the y:ignition and vice versa as the speed decreases. There may be conditions under which the speed of theengine is in' vThe centrifugal device ma ten to advance the position 'of.the cam-re ative to the drive shaft `While the suction-control device may aoI increased. v

tend to retard it.. rThus both devices may act diiferentially ,-tofcontrol the position of the cam 34 relative tothe drive shaft 32 so that the ignition'will betimed properl to correspond'with the engine speed and oad conditions 1 One of theimportant'featuresv ofthe presentinvention is the provision for facilitating the repairs-andreplacements of the devices which control the timing of theignition.

4The centrifugal device may be'vremoved from' the timer without disturbing the suction responsive device. After removing the distributor'head 21v andthe timer Supportingl late 43 the assembly of distributor rotor 25, cam shaf`t`30, intermediate shaft 59 and centrifugal deviceconnecting the shafts may be.

removed from the shaft 32 in assembled relation without disturbing the shaft 32 or the collar 86. Incase it is desired to remove the piston 71 and parts connected therewith including the collar 86, the screws 92 are removed 1n order to permit removal of the plate 91. After this has been done, the piston 71 and the spring 90 may be removed from the cylinder 70.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming Within the scope of the claims which follow.

What is claimed is as follows 1. Ignition apparatus for internal combustion engines comprising, in combination. an interrupter, a cam for operating the interrupter, a drive shaft, a driven shaft connected with the cam and surrounding the drive shaft, means for connecting the two shafts and including a collar slidable along the driven shaft and having a lug extending into a longitudinal slot in one of the shafts and Y into an oblique slot in the other shaft, and a device for moving the collar along the shaft in order to change the angular relation between the shafts.

2. Ignition apparatus for internal combustion engines comprising, in combination, an interrupter, a cam for operating the interrupter, a drive shaft, a driven shaft connected with the cam and surrounding the drive shaft, means for connecting the two shafts and including a collar slidable along the driven shaft and having a lug extending into a longitudinal slot in one of the shafts and ito an oblique slot inthe other shaft, and a device responsive to variations in engine intake suction for moving the collar along the shaft in order to change the angular relation between the shafts.

3. Ignition' apparatus for internal combustion engines comprising, in combination, an interrupter, a cam for operating the interrupter, a drive shaft, a driven'shaft connected with the cam and surrounding the drive shaft, y

means for connecting the two shafts and including a collar slidable along the driven shaft and having alu extending into a longitudinal slot in one o the shafts and into an oblique slot in the other shaft. and a device responsive to variations in engine intake suction for moving the collar along the shaft in order to change the angular relation between the shafts, said device comprising an annular suction chamber surrounding the drive shaft and having a movable annular wall, and comprising means for connecting the wall with the collar while permitting rotation of the collar.

4. Ignition apparatus for internal combustion engines comprising, in combination, an interrupter, a cam for operating the interrupter, a drive shaft, a driven shaft connected with the cam, means for connecting the shafts comprising a collar movable along the shafts and havinga lug extending into grooves inl the shafts, one of the grooves being oblique to the axes of the shafts, and means for mov- 'ing the collarin response to variations in enmsaeaa 3 c of the collar.

5. Ignition apparatus for internal combustion engines comprising, in combination, an interrupter, a cam for operating the interrupter, a drive shaft, a cam-carrying shaft and an intermediate shaft journalled upon the drive shaft, means for connecting the intermediate shaft with one of the other shafts and comprising a collar slidable along the shafts so connected and having a lug extending into grooves in the shafts so connected, one of the grooves being oblique to the axes of the shafts,\a device for moving the collar along the shaft, and other means for connecting the intermediate shaft with another shaft and for varying the anglar relation between them.

6. Ignition appartusl for internal combustion engines comprising, in combination, an interrupter, a cam for operatingthe interrupter,-a drive shaft, a cam-carrying shaft and an intermediate shaft journalled upon lthe drive shaft, means for connecting the intermediate shaft with one of the other shafts and comprising a collar slidable along the shafts so connected, and having a lug extending into grooves in the shafts so connected, one of the grooves being oblique to the axes of the shafts, a device responsive to `engine suction for moving the collar in order to vary the angular relation between the two shafts, and other means for connecting the intermediate shaft with another shaft and for varying the angularl relation between them.

7. Ignition apparatus for internal combustion engines comprising, in combination, an

interrupter, a cam for operating the interrupter, a cam-carrying shaft, an intermediate drive shaft, a main drive shaft extending into the other shafts and providing bearings therefor, means for connecting the inter.

mediate shaft with one of the other shafts and including a collar slidable along the shafts so connected and having a lug extending into grooves in the shafts so connected, one of the grooves being oblique to the axes of the shafts, a device responsive `to engine intake suction for moving the collar in order to change the angular relation between the shafts, and a speed responsive device for connecting the intermediate shaft and another shaft and for varying theangular relation between them.

8. Ignition apparatus for internal combustion engines comprising, in combination, an interrupter, a cam for operating the interrupter, a cam-carrying shaft, an intermediate drive shaft, a main drive shaft extending into the other shafts and providing bearings therefor, means for connecting the vintermediate sha-ft with the drive shaft, and including a collar slidable .along the shafts so connected and having a lug extending into' grooves in the shafts so connected, one of the grooves4 -being oblique to the axes of the shafts, a device responsive to engine intake suction for moving the collar in order to change the angularcrelation between the shafts, and a speed responsive device .for connecting the intermediate shaft with the-camcarrying shaft and for varying the angular relation between them. l

ln testimonywhereof I hereto aflix my signature. WILLIAM CHRYST.

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