US3254247A

US3254247A - Breakerless distributor

Info

Publication number: US3254247A
Application number: US237628A
Authority: US
Inventors: John H Falge
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1962-11-14
Filing date: 1962-11-14
Publication date: 1966-05-31
Anticipated expiration: 1983-05-31
Also published as: GB1062758A; DE1476310A1

Description

May 31,1966 J. H. FALGE 3,254,247

BREAKERLESS DI STRIBUTOR Filed Nov. 14, 1962 2 Sheets-Sheet 1 IN VEN TOR.

y 3 1956 J. H. FALGE 3,254,247

I BREAKERLESS DISTRIBUTOR Filed NOV. 14, 1962 2 Sheets-Sheet 2 Q r INVENTOR.

w 4/0/22? 19. fZz/ye Q I KW HIS ATTORNE y United States Patent M 3,254,247 BREAKERLESS DISTRIBUTOR John H. Falge, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Nov. 14, 1962, Ser. No. 237,628 6 Claims. (Cl. 310-70) This invention relates to a breakerless type of distributor wherein pulses of voltage are generated by the distributor that can be used to control the ignition timing of an internal combustion engine. This application is an improvement of the breakerless distributors shown in copending applications S.N. 95,418, filed on March 13, 1961, now Patent 3,198,973, and SN. 126,406, filed on June 16, 1961, now Patent 3,198,974, both of which are assigned to the ass-ignee of this application.

The present invention is concerned with a breakerless type of distributor wherein pulses of voltage are induced in a coil winding as a magnetic rotor rotates. The magnetic rotor varies the reluctance of a magnetic circuit which is energized with magnetic flux by a permanent magnet. I

One of the objects of this invention is to provide a ibreakerless distributor of a type wherein the permanent magnet is fixed to a shiftable timing plate and wherein the rotor has a plurality of radially extending teeth which cooperate with a pole piece having complementary teeth, the permanent magnet having opposite surfaces which directly contact respectively the pole piece and the timing plate whereby the timing plate serves to adjust the coil winding and permanent magnet and also serves to form part of the magnetic circuit for flux which causes the pulses of voltage to be induced in the coil winding.

Still another object of this invention is to provide a breakerless distributor of the type described wherein the air gap of the magnetic circuit for the pick-up coil is only Patented May 31, 1966 to FIGURE 2, the reference numeral 10 designates a metal base for the distributor and this base includes a tubular section 12 and an annular section 14. The tubular section 12 carries a pair of

bearing bushings

15 and 16 which journal a shaft 18. The

bushings

15 and 16 may be of the porous metal type and are fitted within enlarged bores formed in the tubular portion 12 as is clearly seen from the drawing. The shaft 18 is connected with a gear 20 which serves to drive the shaft when the gear 20 meshes with a suitable gear in an internal combustion engine.

It is seen that the top end of the porous metal bushing 16 extends above the annular section 14 of the base 10. The bushing 16 is lubricated by a wicking material 22 which is located in cavities formed in the upper section 14 of the base 10. This wicking material 22 may be of a type that provides permanent lubrication for the bushing 16 and there may be actually a plurality of circumferentially spaced cavities to receive this wicking material. Where a plurality of pockets or recesses are used, the metal material of the base between the pockets will, of course, provide support for the bearing bushing 16. It is seen that a felt washer 24 together with a suitable seal 26 is used to close off the top of the recesses or pockets. The pockets may be formed, for example, as shown in copending application S.N. 65,069, filed on October 26, 1960,

now Patent 3,162,732, and assigned to the assignee of this invention.

The breakerless distributor of this invention includes a pick-up coil assembly which is generally designated by reference numeral 28. This pick-up coil assembly includes an annular timing plate 30 which is formed of a magnetic material. A pole piece 32 is provided which is formed of a laminated magnetic material such as steel. It is seen from FIGURE 1, that the pole piece 32 has a plurality varied in one annular area. With this arrangement, there located closely adjacent a part of a rotatable pole piece and weight base assembly. In this arrangement, the pole piece and weight base assembly includes the rotary pole piece having radially projecting teeth and includes a cylindrical member which rotates closely adjacent the inner surface of a spool which carries the pick-up coil.

A further object of this invention is to provide a breakerless distributor of a type wherein the timing plate forms a part of the magnetic circuit for the pick-up coil of the distributor but wherein this timing plate is magnetically isolated from the base of the distributor.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 is a view partly in section taken along line 1-1' of FIGURE 2.

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1.

FIGURE 3 is a view partly in section of a pole piece and weight base assembly which is a component part of the breakerless distributor shown in FIGURES 1 and 2.

FIGURE 4 is an end view of the pole piece and weight base assembly shown in FIGURE 3.

Referring now to the drawings and more particularly of V-shaped radially extending pole teeth 34. The distributor of this invention is for an eight cylinder engine and there are therefore eight radially extending pole teeth 34. It will be appreciated that this number of pole teeth can be varied to suit the number of cylinders of the engine.

The laminated pole piece is held together by riveting or by any other suitable arrangement.

A permanent magnet 36 is provided which is annular in configuration and which is clamped between the pole piece 32 and the timing plate 30 by a plurality of fasteners 38 which are threaded into suitable openings formed in the timing plat-e 30. The permanent magnet may be of various types and is magnetized such that its upper and lower ends are of different magnetic polarities. The fasteners 38 pass through slots formed in the permanent magnet 36 and serve to hold the entire pick-up coil assembly'together.

The pick-up coil 40 is wound on a spool 42 that is formed of a suitable plastic insulating material. This spool has an annular section 44 which just fits within the permanent magnet 36. The turns of the coil winding 40 are wound around the longitudinal axis of the spool 42 and these turns lie in a plane which is perpendicular to this longitudinal axis.

The timing plate 30 is secured to an annular bearing part 46 in any suitable manner. This bearing part 46 is journalled on the top end of the bushing 16 and is held from axial displacement by a retainer 49 secured to the top end of the bushing 16. The bearing part 46 serves to journal the entire pick-up coil assembly 28 on the top end of the porous metal bearing 16 and this pick-up coil assembly can therefore be rotated or adjusted relative to the bearing 16 and the base 10. It thus is seen that the pole piece 32 can ;be adjusted around the longitudinal axis of the shaft 18. A washer 50 which is formed of nonmagnetic material is located between the base 14 and the timing plate 30. This washer serves to magnetically isolate the magnetic pick-up assembly 28 from the base 10.

The device for adjusting the pick-up assembly 28 relative to the base comprises a vacuum unit which is generally designated by reference numeral 52. This vacuum unit is entirely conventional and includes a diaphragm 54 which is urged in one direction by a spring 56 disposed between the vacuum unit housing and the diaphragm. The diaphragm is connected with an actuating rod 57. One end 55 of the actuating rod projects through an opening formed in the timing plate 30. This opening is off-set from the longitudinal axis of the timing plate. When the interior of the vacuum unit is connected with the intake manifold of an engine via the pipe 58, the magnetic pickup coil assembly 28 will be rotatably adjusted in accordance with vacuum conditions in the intake manifold. It thus can be seen that the pole piece '32 can be adjusted in accordance with vacuum conditions of the engine.

The breakerless distributor of this invention has a pole piece and weight base assembly or rotor which is generally designated by reference numeral 60. This assembly is better illustrated in FIGURES 3 and 4 and includes a bushing 62, a pole piece 64, and a weight base 66. The pole piece 64 has a plurality of radially extending teeth 64a which correspond in number to the teeth of the pole piece 32. These teeth are once more generally V-shaped as is apparent from an inspection of the drawings.

The pole piece 64 has a central opening which receives the section 62a of the bushing 62. In fabricating the pole piece and weight base assembly 60, the pole piece 64 is slipped over the section 62a until it engages the upper end of section 62b. The pole piece 64 can then be brazed or otherwise secured to the bushing 62. The bushing 62 and the pole piece 64 are formed of magnetic material.

The weight base 66 is brazed, welded or otherwise secured to one end of the section 62a of the bushing 62. The weight base 66 carries posts 68, the purpose of which is more fully described hereinafter.

The bushing 62 has a bore 70 and a counterbore 72.

The pole piece and weight base assembly 60 is assembled such that the counterbore 72 encircles the outer surface of the bearing part 46 with a portion of this counterbore engaging the top end of the bearing bushing 16. The pole piece 64 is positioned such that its radially extending teeth 64a swing in close proximity to the radially extending teeth 34 of the pole piece 32. The section 6212 of the pole piece and weight base assembly 60 rotates in close proximity to the annular wall section 42a of the spool 42.

The upper end of the shaft 18 passes through the bore 76 of the assembly 60 and the assembly 60 is therefore journalled on the shaft 18 and can rotate to some degree with respect to this shaft.

The weight base section 66 of the assembly 60 forms a part of a conventional centrifugal advance mechanism which is operative to adjust the assembly 60 relative to the shaft 18 in response to speed'of rotation of this shaft. This centrifugal advance mechanism can include a cam plate 73 which is rigidly secured to theupper end of the shaft 18. This cam plate carries a pair of posts one of which is illustrated and designated by reference numeral 74. The post 74 is connected to one of the posts 68 by a spring 76. The post 68 forms a pivot for a fly weight 78 which has an inner surface that is engageable with the cam plate. It, of course, will be appreciated that another fiy weight is provided together with another post 74 and another spring 76. This entire centrifugal advance mechanism can therefore be of a type shown in the above mentioned co-pending application S.N. 126,406 and can be of a type shown in the Hartzell et al. patent, 2,872,537.

The centrifugal advance mechanism is enclosed by a rotor 77 having a body portion 79 which is formed of insulating material and which is secured to the weight base 66 by the fasteners 80. 82 and 84 which are electrically connected together. The electrode 84 is formed of resilient material and is in electrical contact with the insert 86 which is formed of elec- The portion 77 carries electrodes trically conductive material and which forms the center electrode of the distributor cap 88. The distributor cap 88 is of conventional construction in that it is formed of a plastic insulating material and has the center insert 86 and eight equally circumferentially spaced outer inserts 90. The electrode 82 swings in close proximity to the outer inserts or electrodes 90 in a manner well known to those skilled in the art. There are eight electrodes 90 and one center electrode 86 for an eight cylinder engine.

The pick-up coil 40 terminates in

conductors

92 and 94 which pass through a grommet 96 located in an opening in the upper section of the base 10. The

lead wires

92 and 94 are connected with terminals located in a connector 98 that is formed of insulating material. These connectors may take the form of male terminals which can be suitably plugged into female terminals.

When the shaft 18 of the breakerless distributor of this invention is rotated, pulses of voltages are induced in the coil winding 40. These pulses of voltage can then be used to trigger a control unit which in turn controls the firing of the spark plugs of an internal combustion engine. This control unit may be, for example, of the type shown in co-pending application, S.N. 95,161, now Patent 3,087,- 001, filed on March 13, 1961, and assigned to the assignee of this invention.

As the shaft 18 rotates, it is seen that the pole piece 64 will rotate therewith. When the teeth 64a of the pole piece 64 are aligned withthe teeth 34 of the pole piece 32, a magnetic circuit can be traced for example from the top end of the permanent magnet 36, through the pole piece 32, through the pole piece 64, through the section 6212 of the pole piece and weight base assembly 60, through an air gap between an annular end of the section 62b and the timing plate 30 and then through the timing plate 30 to the opposite end of the permanent magnet 36. It will, of course, be appreciated that as the teeth 64a move out of alignment with the teeth 34, the reluctance of the magnetic circuit is increased. As a result, there are eight pulses of voltage induced in the pick-up coil 43 for every revolution of the pole piece 64.

The timing of the voltage pulses can be varied in accordance with the speed of rotation of the shaft 18. Thus, the centrifugal advance mechanism adjusts the assembly 60 relative to the shaft 18 as a function of the speed of rotation of this shaft. As a result of this, the rotatable pole piece 64 is adjusted relative to the shaft 18 and the entire train of voltage pulses is therefore shifted in relationship to crank shaft angle of the engine. The centrifugal advance mechanism will advance the voltage pulses as the speed of shaft 18 increases.

The timing of the voltage pulses is also adjusted in accordance with engine load conditions by means of the vacuum unit 52. Thus as the vacuum in the intake manifold of the engine increases, the pick-up coil assembly 28 will be adjusted in a clockwise direction around the axis of the shaft 18 and relative to the rotatable pole piece 64. It thus is seen that the pole piece 32 will be adjusted relative to the pole piece 64 by the vacuum control unit 52.

From the foregoing, it can be seen that the output voltage that can be taken from

leads

92 and 94 will be a series of voltage pulses which are controlled both by the speed of rotation of the shaft 18 and the amount of vacuum applied to the vacuum unit 52.

While the embodiments of the present invention as herein disclosed, constitute a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A breakerless distributor comprising, a base member, a shaft journalled for rotation in said base member,

a timing plate formed of magnetic material adjustable relative to said base member, an annular permanent magnet having opposite end surfaces of opposite magnetic polarity, one end of said permanent magnet directly engaging said timing plate, a pole piece directly engaging the opposite surface of said permanent magnet having a plurality of circumferentially spaced radially inwardly extending teeth, a coil winding assembly including a coil winding wound on a coil form clamped between said pole piece and said timing plate having a central opening, and a rotor member driven by said shaft having an annular section disposed within said opening in said coil winding assembly, said annular section having an end face forming a fixed air gap with said timing plate, said rotor member having a portion formed with a plurality of radially outwardly extending teeth which form an air gap with the teeth of said pole piece, said rotor member carrying a plate which forms a part of a centrifugal advance mechanism which is operative to adjust said rotor member relative to said shaft in accordance with shaft speed.

2. A breakerless distributor comprising, a base member having a bore, a bearing disposed within said bore having a portion projecting beyond one end of said base, a timing plate rotatably supported by said bushing and ad justable relative to said shaft, said timing plate being formed of magnetic material, an annular pole piece formed of magnetic material having radially inwardly and circumferentially spaced teeth, an annular permanent magnet having opposite end surfaces directly engaging respectively said timing plate and said pole piece, an annular coil winding assembly disposed between said timing plate and said pole piece, said coil winding assembly having a central opening, and a rotor member driven by said shaft, said rotor member including a first annu- 'lar section disposed within said opening in said coil winding and between said coil winding and said bushing, said first annular section having an end face that has a constant air gap with said timing plate when said rotor rotates, said rotor member including a second section having radially extending teeth which are circumferentially spaced, said second section being aligned with said pole piece and located at least partially above said coil winding, said rotor member having a third section which forms a part of a centrifugal advance mechanism for adjusting said rotor member relative to said shaft in response to said shaft speed.

3. A breakerless timing device for controlling an ignition system comprising, a base, said base having a bore, a cylindrical bushing disposed within said bore, a shaft journalled for rotation in said bushing, a timing plate formed of magnetic material rotatably supported on an outer surface of said bushing for rotation relative to said bushing, a pole piece formed of magnetic material having a plurality of radially inwardly extending teeth which r are circumferentially spaced from each other, an annular permanent magnet having opposite end surfaces directly engaging respectively said pole piece and said timing plate, a coil winding assembly disposed between said pole piece and said timing plate having a central opening, a rotor driven by said shaft, said rotor having a first section disposed between said bushing and said coil winding, the end face of 'said first section having a predetermined air gap with said timing plate, said rotor member having a second section of reduced diameter extending axially from said first section, a rotor plate having a plurality of radially outwardly extending teeth fixed to said first and second sections at a point where said sections change diameter, the teeth of said rotor plate being located in alignment with the teeth of said pole piece and having a predetermined air gap therewith, and a second plate member secured to said rotor member forming part of a centrifugal advance mechanism for adjusting said rotor relative to said shaft.

4. The timing device according to claim 3 where a non-magnetic part is disposed between the timing plate and the top end of said base.

5. A voltage pulse generating device for controlling an ignition system for an internal combustion engine comprising, a base, a shaft rotatably supported by said base, a timing plate formed-of magnetic material supported by said base, a pole piece formed of magnetic material having a plurality of radially inwardly extending teeth which are circumferentially spaced, an annular permanent magnet having opposite ends directly engaging respectively said pole piece and said timing plate, and a rotor member formed of magnetic material driven by said shaft, said rotor member having a first section formed with a plurality of radially outwardly extending teeth which are circumferentially spaced from each other and which are aligned with the teeth on said pole piece, said rotor member having a second section located within said coil winding the end face of which has a substantially constant air gap with said timing plate as said rotor member rotates, said timing plate forming a magnetic circuit between said one end of said rotor part and one end face of said annular permanent magnet.

6. A breakerless distributor comprising, a base having a bore, a bushing disposed within said bore having a portion projecting beyond one end of said base, a distributor cap having a plurality of circumferentially spaced electrodes and a center electrode carried by said base and defining a compartment with said base, a timing plate formed of magnetic material rotatably supported on the outer surface of said portion of said bushing, a pole piece formed of magnetic material having a plurality of radially inwardly and circumferentially spaced teeth, an annular permanent magnet having opposite end surfaces directly engaging respectively said pole piece and said timing plate, a coil winding assembly located between said pole piece and said timing plate and having a central opening, a shaft disposed Within said bushing adapted to be rotatably driven by an engine, a rotor member including a first section located Within the bore of said coil winding and having an end face which is spaced from said timing plate to form a predetermined air gap therewith, said rotor including a second part having a plurality of radially outwardly extending teeth which are aligned with the teeth on said pole piece, said rotor having a third part which forms a part of a centrifugal advance mechanism which is adapted to drive said rotor from said shaft and which is operative to adjust said rotor relative to said shaft in response to shaft speed, and an insulator supported by said third part of said rotor carrying an electrical contact means which is operative to sequentially connect the center electrode of said distributor cap and circumferentially spaced electrodes.

References Cited by the Examiner 0 MILTON O. HIRSHFIELD, Primary Examiner.

A. J. ROSSI, Assistant Examiner.

Claims

1. A BREAKERLESS DISTRIBUTOR COMPRISING, A BASE MEMBER, A SHAFT JOURNALLED FOR ROTATION IN SAID BASE MEMBER, A TIMING PLATE FORMED OF MAGNETIC MATERIAL ADJUSTABLE RELATIVE TO SAID BASE MEMBER, AN ANNULAR PERMANENT MAGNET HAVING OPPOSITE END SURFACES OF OPPOSITE MAGNETIC POLARITY, ONE END OF SAID PERMANENT MAGNET DIRECTLY ENGAGING SAID TIMING PLATE, A POLE PIECE DIRECTLY ENGAGING THE OPPOSITE SURFACE OF SAID PERMANENT MAGNET HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED RADIALLY INWARDLY EXTENDING TEETH, A COIL WINDING ASSEMBLY INCLUDING A COIL WINDING ON A COIL FORM CLAMPED BETWEEN SAID POLE PIECE AND SAID TIMING PLATE HAVING A CENTRAL OPENING , AND A ROTOR MEMBER DRIVEN BY SAID SHAFT HAVING AN ANNULAR SECTION DISPOSED WITHIN SAID OPENING IN SAID COIL WINDING ASSEMBLY, SAID ANNULAR SECTION HAVING AN END FACE FORMING A FIXED AIR GAP WITH SAID TIMING PLATE, SAID ROTOR MEMBER HAVING A PORTION FORMED WITH A PLURALITY OF RADIALLY OUTWARDLY EXTENDING TEETH WHICH FORM AN AIR GAP WITH THE TEETH OF SAID POLE PIECE, SAID ROTOR MEMBER CARRYING A PLATE WHICH FORMS A PART OF A CENTRIFUGAL ADVANCE MECHANISM WHICH IS OPERATIVE TO ADJUST SAID ROTOR MEMBER RELATIVE TO SAID SHAFT IN ACCORDANCE WITH SHAFT SPEED.