close

Вход

Забыли?

вход по аккаунту

?

Патент USA US3098376

код для вставки
July 23, 1963
R. K. FRANK
3,098,366
IGNITION DISTRIBUTOR
Filed NOV. 16, 1961
4 Sheets-Sheet l
28
40
/06
/04‘
‘I I4
5
46
30
INVENTOR.
A’O?E/PT K. F/PA/VK
ATTORNEY
July 23, 1963
R. K. FRAYNK
3,098,366
IGNITION DISTRIBUTOR
Filed Nov. 16, 1961
'
§
4 Sheets-Sheet 2
52
28
4
\
l‘ I
4‘
l
442
_
I
l—-
i
:f'
/
‘
/
_-|
%
‘70
90
5 I
5
30
°
86
38
88
32
INVENTOR.
RO6EA’7' A’. FRA/VK
BY
ATTORNEY
July 23, 1963
R. K. FRANK
3,098,366
IGNITION DISTRIBUTOR~
Filed Nov. 16, 1961
4 Sheets-Sheet 3
147'7'O/P/VEY
July 23, 1963
R. K. FRANK
3,098,366
IGNITION DISTRIBUTOR
Filed Nov. 16, 1961'
4 Sheets-Sheet 4
yyaaeza WV.) /1// JIM/may yaw/.9
INVENTOR.
ROBERT A’. FRANK
BY
Va’ /9
(12%?’ TOR/V5)’
United States Patent 0
ce
3,098,366
Patented July 23, 1963
1
2
3,998,366
eliminated with the use of the proposed slider block. It
was believed that this was due in part to the edges of the
slots having machine marks extending in one direction
IGNITION DISTRIBUTGR
Robert K. Frank, Mount Clemens, Mich, assignor to
Holley Carburetor Company, Warren, Mich, a corpo
ration of Michigan
Filed Nov. 16, 1961, Ser. No. 152,829
6 Claims. (CI. 64—25)
or the other, depending upon the direction of the machin
ing; this roughness was su?icient to give a different coef?
cient of friction when the pin was moving along the edge
of the slot in one direction than when the pin was moving
in the other direction. The surface of the self-lubricating
This invention relates to ignition distributors, and more
slider block appeared to merely glide over the high spots
particularly to an improvement in ignition distributors of 10 of this roughened surface on the edges of the slots so as
the type in which spark advance is effected in whole
to more nearly result in a constant coe?‘icient of friction,
or in part by the action of centrifugal weights driven in
regardless of the direction of movement.
accordance with engine speed.
It was also pointed out that both the pins and the
In a number of ignition distributors commercially avail
weights in present day prior art distributors have to be
able today, a pin extending from each of the centrifugal 15 hardened, in most cases to somewhere around RG55 as a
weights slides in a slot formed therefor in an arm extend
ing laterally from the distributor cam.
An alternate con
struction employs suitably oriented slots formed in the
centrifugal weights; in this case, the pins sliding in the
weights are formed on or secured to each arm of the dis
tributor cam member.
In either case, the geometry of
this pin and slot linkage is such that it produces the de—
sired cam rotation to weight displacement (spark ad
vance) characteristic.
minimum. This hardening is an expensive step in the
manufacture of the distributor. With the use of the softer
Delrin or other material for the slider block proposed in
application Serial No. 143,277, neither the pins nor the
slots have to be hardened; rather, they can be used in their
unhardened and machined condition.
While the structure proposed in application Serial No.
143,277 very effectively eliminated the above mentioned
problems with prior art distributors, it still requires the
A distributor of this kind in which the pins are formed 25 forming or securing of pins, either on the centrifugal
on the distributor cam member is disclosed in US. appli
weights or on the arms extending from the distributor
cation Serial No. 84,254 ?led on January 23, 1961, in the
cam member. This has now been found to be an unneces
names of Eugene C. Bettoni and Ernest R. Larges.
sary expensive step in the production of distributors of
While distributors of this kind have been generally suc
this kind. Also, the combination pin and slider block
cessful in their operation, the use of a cylindrical pin in a
is a two-piece construction which also adds to the expense.
slot having parallel and straight edges results in straight
Accordingly, an object of this invention is to eliminate
line contact between the pin and the wall of the slot. This
the above recited objections to prior art distributors.
relatively small contact area results in very large bearing
Another object of the invention is to provide a dis
stresses due to vibratory conditions due to engine tor
tributor construction in which the attachment of pins and
sionals and the reaction of the cam to the rubbing block 35 the two-piece pin and slider block construction are elimi
forces, even at light loads. These high bearing stresses
nated.
often cause severe wear of both the pin and the slot.
A still further object of the invention is to substitute a
The above-mentioned wear in turn results in a number
of highly undesirable effects in the function of the spark
single-piece combination pin and slider block for the pre
viously proposed two-piece assembly.
40
advance mechanism, as follows:
Other objects and advantages of the invention will be
(1) The distributor provides a different amount of
come more apparent when reference is made to the fol~
spark advance for a given r.p.m. depending upon whether
lowing description and the accompanying drawings,
the engine was accelerated or decelerated to reach the
wherein:
FIGURE 1 is a top plan view of a prior art ignition
given r.p.m.
-(2) The distributor fails to follow the original desired 45 distributor to which the invention may be applied so as to
relationship between spark advance and r.p.m.
improve the operation thereof;
In US. application Serial No. 143,277 entitled, “\Igni
FIGURE 2 is a cross-sectional view taken substantially
tion Distributor,” and ?led on October 4, 1961, in the
on the plane of line 2—2 of FIGURE 1 and looking in
name of ‘Ian I. C. Scott, it was proposed to eliminate the
the direction of the arrows;
.
above undesirable effects and to greatly increase the life 50
FIGURE 3 is a cross-sectional view taken on the plane
of a distributor of this kind and insure its continued orig
of line 3-3 of FIGURE 2 and looking in the direction of
inal proper performance. In the particular embodiment
the arrows;
of the invention disclosed therein, this was acocmplished
FIGURE 4 is a view similar to FIGURE 3 wherein the
by enlarging the above-mentioned slots and providing a
distributor centrifugal advance mechanism has been modi
so-called slider block having oppositely disposed ?at outer 55 ?ed to embody the invention;
surfaces and being made of any suitable wear-resistant
FIGURE 5 is a cross-sectional view taken on the plane
and self-lubricating material, such as Delrin, between the
of line 5—5 of FIGURE 4 and looking in the direction of
pin and the slot. In other words, the slider block was
the arrows;
formed in a manner so that it could be assembled over the
FIGURE 6 is a view similar to FIGURE 5 illustrating
pin and be inserted into the slot, thus increasing the con
the application of the invention to a dis-tributor in which
tact surface area between the pin and the slot. Wear was
certain parts are reversed;
thus drastically reduced and/or virtually eliminated, and
FIGURE 7 is anenlarged perspective view of the com
the useful life of the distributor and advance mechanism
bination pin and slider block element embodying the
was greatly prolonged.
invention;
‘It was also pointed out in the above referenced appli 65
FIGURE 8 is a graph illustrating the ignition advance
cation Serial No. 143,277 that even in a new and properly
characteristics of an ignition distributor before and after
operating prior art distributor such as that shown in ap
the above-mentioned wear that use of the invention elim
plication Serial No. 84,254 there is some hysteresis be
inates.
tween the increasing speed and the decreasing speed
As already stated above, FIGURES 1-3 illustrate one
spark advance curves; this is so, even though both curves 70 of the present-day distributors to which the invention may
are within the prescribed limits. However, it was found
be applied. For purposes of clearly distinguishing the
that this hysteresis was greatly reduced and/or entirely
invention from the prior art, this prior art distributor will
3,098,366
3
?rst be described. Following that, the manner in which
the invention may be applied to this and other prior art
distributors will be described.
Referring now to the drawings, FIGURES 1~3 illus
4
It is to be noted that the cylindrical pins 96 and 98 have
only vertical line contact with the usually straight sides or
edges of the slots 92 and 94 and that it occurs on either
side of the slot, depending upon the direction in which the
weights are moving. This line contact between each
cylindrical pin and the straight-edged slot is necessary be
cause the pin is rigidly secured to the weight and the
bustible mixtures therethrough and into the engine intake
movement of the centrifugal advance mechanism is such
manifold 16. Port 18 communicates with the induction
that providing a pin with ?at sides would cause binding
passage 12 and with the chamber 22 of the vacuum motor
24, as by means of a suitable conduit 26.
10 and improper operation of the mechanism.
Assuming now that the ?yweights have been positioned
The ignition distributor 28 is comprised generally of a
trate a carburetor 10 having an induction passage 12 and
a throttle valve 14 adapted to control the flow of com
cup-shaped housing 30 including a depending reduced
in accordance with engine speed, any part throttle position
will cause vacuum to be communicated from ori?ce 18 to
portion 32 having an opening 34 therethrough for the re
chamber 22 and accordingly move the diaphragm 66 to
ception of a driving shaft 36. A bushing-like bearing
member 38 may be provided in order to reduce the degree 15 the left against the force of spring 74. The degree to
which diaphragm 66 moves is basically a function of the
of friction between the rotating shaft 36 and surface of
manifold (engine) vacuum and the spring rate of spring
opening 34.
A base plate 40, rigidly secured to the housing 30 as
74.
As diaphragm 66 moves to the left, member 68 being
by means of screws 42, retains a pivot member 44 to
which the breaker plate 46 is pivotally secured. The 20 secured thereto also moves an equivalent amount thereby
causing breaker plate 46 to move in a generally clockwise
breaker plate 46 carries thereon a breaker arm assembly
direction about its pivot member 44. This movement
48 which includes a cam engaging portion 50 engageable
results in the lobes of cam member 52 engaging the cam
by the rotating cam 52 to effect make and break of the
engaging portion 50 at ever increasing degrees of crank
circuit at the contacts indicated at 54. The cam 52 is
mounted on the shaft 36 for limited rotation with respect 25 shaft rotation ahead of top dead center.
From the above it is evident that the ignition distribu
thereto, but so as to be rotated thereby. The shaft 36
tor provides speed responsive means for adjusting the
is, of course, rotated in timed relation with the engine
position of cam member 52 with respect to the shaft 36
56 by means of gear member 58 cooperating with some
and separate pressure responsive means for rotating the
output transmission 60 of the engine.
The pressure responsive device 24 is substantially com 30 breaker plate 46 and ignition contact arm assembly 48 in
order to arrive at an ignition advance which is re?ective
prised of a housing 62 and cover member 64 rigidly held
together in a manner so as to peripherally secure a dia
phragm member 66 therebetween. A member 68, con
nected at its one end to the diaphragm member 66, is
of both engine load and speed.
Reference will now be made to FIGURES 4-7 which
illustrate how the invention is applied to the prior art dis
adapted to be operatively engaged with breaker plate 46, 35 tributor of FIGURES 1-3. FIGURE 4 is, of course, a
as by means of a hole formed therein for the reception
view similar to FIGURE 3, and all the identical elements
of a connecting link 70‘ which pivotally secures the mem
ber 68 and breaker plate 46 to each other. Chamber 22,
formed generally by cover 64 and diaphragm 66 is ex
posed to a source of vacuum, as communicated by con
duit 26, while chamber 72 is vented to the atmosphere. A
calibrating spring 74 is also located within chamber 22
are identi?ed with the same reference numerals.
It is believed that the invention can best be descibed
by initial reference to FIGURE 7 which illustrates the
40 single-piece combination pin and slider block element 110
contemplated by the invention. The element 110 com
prises a body preferably formed of some abrasion-resist
in a manner so as to resiliently oppose the movement of
ant and self-lubricating material that is not as hard as
diaphragm 66 in response to increases in vacuum. The
the material from which the centrifugal weights 78 and
80 or the member 90 extending laterally from the dis~
entire pressure responsive devce 24 can, of course, be se
cured to the housing 30 by any suitable means‘such as 45 tributor cam 52, in either of which the slots 92 and 94
may be formed, are constructed. A material found to
screws 76.
The speed responsive portion of the ignition advance
be very suitable for the construction of the element 110
mechanism, as illustrated generally by FIGURE 3, is sub
is a relatively new plastic material known as “Nylatron."
stantially comprised of ?yweight members 78 and 80
The element 110 is preferably constructed so as to have
which are pivotally mounted, as by pivot members 82 and
three sections: a cylindrical pin section‘ 112 at one end,
84, respectively, to a base member 86. The base mem
a somewhat larger cylindrical section 114 having oppo
ber is rigidly secured by any suitable means such as a
sitely disposed parallel ?at surfaces 116 at the other end,
and a laterally extending ?ange section 118 of greater
A cam plate 90, rigidly secured to the lower portion of
diameter than either of the two end sections.
cam member 52, has slots 92 and 94 formed therein, 55
Referring now to FIGURES 4 and 5, which illustrate
which are adapted to cooperate with cylindrical pin-like
one use of the member 110 shown‘ by FIGURE 7, it is
members 96 and 98 secured within or to ?yweight mem
apparent that the prior art steel or other pins 96 and 98
bers 78 and 80. Calibrating springs 100 and 102 an
shown in FIGURE 3 as being attached to the centrifugal
chored at one end to the base member 86 are provided to
weights 78 and 98, respectively, are eliminated. Rather
resist the outward movement of the ?yweights 78 and 80 60 the weights 78 and 80 are merely drilled or otherwise
as engine speed increases.
>
formed to provide bores 120 where the pins 96 and 98
The ignition distributor, as illustrated by FIGURES 1,
would otherwise be located, and the cylindrical end 112
2 and 3, is shown in full retard, as it would be when the
of the slider block and pin element 110 is inserted into
engine is running at curb idle.
each one of these bores until the ?ange 118 engages the
As engine speed increases, the rotational speed of shaft
upper surface of the weight. The element 90 attached
36 will correspondingly increase, and the ?yweights 78
to the cam 52 is then assembled over the weights 78 and
and 80 will travel arcuately outwardly about their pivots
80 in a manner so that the opposite end 114 of the ele—
82 and 84. As the ?yweights move outwardly, the mo
ment 110 extends into the slot 92 with the ?at surfaces
tion transmitting links or pins 96 and 98 rotate cam plate
116 engaging the edges of the slot. The ?t, between‘ the
90 and cam member 52 counterclockwise with respect to 70
cylindrical end 112 of the element 110 and bore 120 in
shaft 36, thereby causing an advance which is generally
the weight is such that the element 110 can rotate freely
related to the increase in engine speed. The forces
with respect to the weight. This being so, the inward
which restrict outward movement of the ?yweights are, of
or outward movement of the weights causes a correspond~
course, due to the resistance offered by the tension springs
100 and 102.
75 ing angular adjustment of the element 90, and the cam
collar member 88 to the shaft 36 so as to rotate therewith.
3,098,366
6
52 to which it is attached, so as to advance or retard the
spark in the same manner as explained above in connec
tion with the prior art construction.
The combination pin and slider block element 110' is
very easily and inexpensively formed from any appro
priate material, and it is apparent that the elimination of
the pins 96 and 98 represents a considerable saving in
the cost of manufacture of this distributor spark advance
likely to occur in the elements 110 which are very in
expensive and very easily replaced. This is to be con
trasted with prior art distributors wherein wear requires
replacement of either the weights or the cam member,
since it is not practical to replace the pins ‘alone inasmuch
as they are either brazed or otherwise permanently se
cured to one of the elements of the spark advance mech
anism.
While but two modi?cations of the invention have been
mechanism. Since the element 110 is rotatable in the
weights, the element has freedom of movement so as to 10 shown and described, it is apparent that other modi?ca
prevent any binding inthe sliding action between the flat
tions may be made. For example, it is conceivable that
surfaces 116 of the element 110 and the edges of the
the element 110 may not in all cases require the oppo
slots 92. No hardening of any of the parts is required
sitely disposed ?at surfaces 116 in view of the fact that
since the elements 110 are made of a softer material, and
it is rotatable in its support, and no limitations are in
the element 110 has been found to require no lubrication 15 tended except as recited in the appended claims.
or experience any appreciable Wear. The self-lubricating
What I claim as my invention is:
properties of the elements 110 and the provision of the
1. An ignition distributor comprising a drive shaft, a
?at surfaces thereon reduces the possibility of “fretting
pair of centrifugal weights pivoted on said shaft, a dis
corrosion,” which causes mating parts subjected to high
tributor cam driven by and mounted for limited rotation
frequency and high unit load vibrations to wear due to
with respect to said shaft, said cam having a pair of
the formation of oxides. Any roughness on the edges
arms extending therefrom in opposite directions, an
of the slots 92 does not materially increase the friction
angularly disposed slot form in each of said arms, and a
between these edges and the slider block portion 114 of
pin rotatably mounted in each of said weights and hav
the member .110- due to the surface contact, rather than
ing the free end thereof disposed in one of said slots,
the line contact, between these elements.
25 the end of said pin disposed in said slot having oppositely
FIGURE 6 is a view similar to FIGURE 5, except that
the slots 92 are formed in the weights 78 and 80, rather
‘disposed parallel ?at surfaces for engagement with the
edges of said slot.
2. An ignition distributor comprising a drive shaft, a
pair of centrifugal weights pivoted on said shaft, a
than in the member 90. This being so, the cylindrical
portion 112 of the element 110 is ?tted into bores 120
formed in the member 90' with sufficient clearance to 30 distributor cam driven by and mounted for limited ro
permit rotation of the element 110 during the operation
tation with respect to said shaft, said cam having a pair
of the advance mechanism. In this particular modi?ca
of arms extending therefrom in opposite directions, an
tion, the intermediate ?ange 118 of the element 110, the
angula-rly disposed slot formed in each of said weights,
diameter of which is greater than the width of the slots
and a pin rotatably mounted in each of said varms and
92, prevents the element 110 from falling through the 35 having the free end thereof disposed in one of said
slots 92. Otherwise, the operation of FIGURE 6 is the
slots, the end of said pin disposed in said slot having
same as that of FIGURES 4 and 5.
oppositely disposed parallel ?at ‘surfaces ‘for engagement
The overall operation of the distributors embodying
with the edges of said slot.
3. An improvement in an ignition distributor of the
same ‘as that of the prior art distributor shown in FIG 40 type in which angular adjustment of the distributor cam
URES 1-3. It is apparent, however, that the line con
with respect to the distributor drive shaft on which the
tact of FIGURE 3 between pins 96 and 98 and the slots
cam is mounted is accomplished by the action between
92 and 94, respectively, has been changed to a sliding
centrifugal weights pivotally mounted on said shaft and
the invention, ‘as shown in FIGURES 4-7, is exactly the
surface contact in FIGURES 4 and 5. The same is true
arms extending from said cam due to a pin extending from
in FIGURE 6.
45 one of said elements and being in engagement with suit
As already stated above, line contact between the prior
art pins and slots results in very high or concentrated
stresses so that normal vibrations occurring in the ad
vance mechanism tend to and do deform the pins and the
edges of the slots to the extent that the advance mecha
nism cannot operate properly. This malfunction due to
Wear is graphically illustrated in FIGURE 8, wherein the
curves A and B represent the acceptable limits of spark
advance vs. engine speed, the curves C and D illustrate
ably disposed slots formed in the other of said elements,
said improvement comprising said pins being formed and
mounted on one of said elements so as to be rotatable
with respect thereto, the free end of each of said pins
received in one of said slots being formed with oppositely
disposed flat surfaces to engage the edges of said slot.
4. An improvement in an ignition distributor of the
type in which angular adjustment of the distributor cam
with respect to the distributor drive shaft on which the
the performance of a new distributor and curves E and F 55 cam is mounted is accomplished by the action between a
illustrate the deviation even from the acceptable limits
centrifugal weight pivotally mounted on said shaft and
an arm extending from said cam due ‘to ‘a pin extending
in a prior art distributor (FIGURES l-3) that has been
subjected to the ‘above Wear mentioned. FIGURE 8 was
from one of said elements and being in engagement with
prepared from actual test data.
a suitably disposed slot formed in the other of said ele
While the purpose of the invention is, of course, to 60 ments, said improvement comprising said pin being
maintain the operation of the distributor advance mecha
formed and mounted on one of said elements so as to be
nism within the acceptable limits (curves A and B of
rotatable With respect thereto, the free end of said pin
FIGURE 8) throughout the distributor life, it has been
received in said slot being formed on opposite sides
found that substantially original performance (curves C
thereof so as to provide area rather than line sliding con
and D of FIGURE 8) is achieved; in fact, the hysteresis 65 tact with the edges of said slot.
found even in a new prior art distributor is eliminated in
5. An ignition distributor, comprising a drive shaft, a
many instances.
centrifugal weight element pivoted on said shaft, a dis
From the above description, it should be apparent that
tributor cam driven by and mounted for limited rotation
a distributor embodying the invention is superior in per
with respect to said shaft, said cam having an arm ele
formance as compared to prior art distributors, has longer 70 ment extending therefrom, a suitably disposed edge
life and is less expensive to manufacture and maintain in
formed on one of said elements, and a pin rotatably
repair. With the use of the relatively soft combination
mounted on the other of said elements and having the
pin and slider block elements 110, no wear occurs in the
free end thereof engaging said edge, the end of said pin
cooperating metal parts such as the weights and the cam
engaging said edge being formed to provide area rather
member. If any wear or other damage occurs, it is most 75 than line engagement with said edge.
3,098,366
7
8
.
end of said pin engaging said edge being formed on one
6. An improvement in an ignition distributor of the
side thereof so as to provide area rather than line sliding
type in which angular adjustment of the distributor cam
contact with said edge.
with respect to the distributor drive shaft on which the
cam is mounted is accomplished by the action between
References Cited in the ?le of this patent
a centrifugal weight element pivotally mounted on said 5
shaft and an arm element extending from said cam due
UNITED STATES PATENTS
to a pin extending from one of said elements and being
1,029,026
Newman ____________ __ June 11, 1912
in engagement with a suitably disposed edge formed on
1,938,655
Gibson ______________ __ Dec. 12, 1933
the other of said elements, said improvement comprising
said pin ‘being formed and mounted on one of said ele 10
ments so as to be rotatable with respect thereto, the free
2,196,360
2,977,778
Kamenarovic ___________ __ Apr. 9, 1940
Backlund et al __________ __ Apr. 4, 1961
Документ
Категория
Без категории
Просмотров
0
Размер файла
758 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа