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Патент USA US3040733

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June 26, 1962
Filed March 11, 1960
F==_E a
Unite States
Patented June 26, 1962
the injection point which increases the operational relia
bility thereof.
Hans O. Scherenberg, Stuttgart-Heumaden, and Johannes
Another object of the present invention is the provi
sion of an adjusting mechanism for adjusting the timing
Gassmann, Altbach (Neclrar), Germany, assignors to
Daimier-Benz Aktiengesellschaft, Stuttgart-Unterturlr- '
heim, Germany
Filed Mar. 11, 1960, Ser. No. 14,317
Claims priority, application Germany Mar. 19, 1959
4 Claims. (Cl. 123-139)
The present invention relates to an adjusting installa
tion for adjusting the time of the point of injection for
injection pumps provided with a drive means in the form
of a camshaft and a tappet for internal combustion en
The present invention aims at a structural simpli?ca
tion of an adjusting installation for adjusting the time of
the injection point of the type mentioned hereinabove
and to render the same less expensive as well as to in
of the injection point of a fuel injection pump which is
provided with 1a cam-driven tappet or plunger in which
the forces ‘and stresses particularly in the tappet end and
the part operatively connected therewith are advantageous
ly distributed to avoid any peak stresses.
These and other objects, features and advantages of
the present invention will become more obvious from the
following description when taken in connection. with the
accompanying drawing which shows, for purposes of illus
tration only, two embodiments in accordance with the
15 present invention and wherein:
FIGURE 1 is a cross-sectional view through a ?rst em
bodiment of an adjusting mechanism in accordance with
the present invention and, more particularly, through the
tappet guide means thereof provided with an eccentric
20 bushing, and
crease the reliability of operation thereof.
The present invention is particularly intended for en
FIGURE 2vis a cross-sectional view through a modi?ed
gine constructions in which the camshaft and the engine
embodiment of van adjusting mechanism in accordance
control shaft form an integral part.
with the present invention provided with a tappet guide
The present invention essentially consists in arranging
means having a pivotal arm.
the tappet guide means so as to the movable, preferably,
Referring now to the drawing, wherein like reference
rectangularly in relation to the camshaft. In connection
numerals are used throughout the two views to designate
therewith, provision may be made so as to render the tap
pet movable and adjustable essentially rectangularly with
like parts, FIGURES 1 and 2 illustrate a tappet drive
arrangement which consists of a cam 1 and of a .roller
respect to the camshaft axes by means of a toothed rack
member 2 normally riding along the cam surface of cam
of a worm drive or the like within a predetermined range 30. 1. As the cam 1 rotates in the direction of arrow 3,
into any desired positions.
The following structural basic concepts for the con
struction of the tappet guide arrangement in accordance
with the present invention have proved themselves as par
the roller member 2 follows along the surface 4 of
cam 1, as is well known.
The roller member 2 is ‘arranged at the lower end of
the tappet 5 which is adapted to reciprocate in the up
3,5 ward and downward directions corresponding to the double
On the one hand, the tappet guidance may be arranged
arrow 6,;and more particularly, which is adapted to carry
within an eccentric bushing which is adapted to be rotated,
out such reciprocatory movements ‘with the aid of or in
preferably over a gear rim and toothed rack connection.
opposition to the force exerted thereon by the coil spring
, ticularly appropriate:
On the other hand, the entire tappet guide arrangement
7. The coil spring 7 is disposed within a bushing 8
may be adapted to be pivoted preferably about an axis 40 rigidly connected with the support of the roller member
disposed essentially parallel to the camshaft axis.
2 which support may ‘be of any known suitable construc
In order to attain, with a pivotal tappet guide means,
a loading of the upper tappet end which is as satisfactory
The bushing 8 is adapted to slide within a relatively
and unobjectionable as possible, and in order to attain
stationary bushing 9 in the embodiment of FIGURE 1
a simple ‘bearing support of the structural parts constitut 45 which bushing 9, in turn, is surrounded by an eccentric
ing effectively the pivot axis, the pivot ‘axis in accordance
bushing 10. The eccentric bushing 10 is rotatably sup
with the present invention is advantageously located at
ported within the housing block 11. The rotation of
the upper end or within the region of the upper end of
the eccentric bushing 14} takes place over the gear-rim
the tappet.
toothed-rack connection consisting of the gear rim 12 pro
For purposes of transmitting the control magnitude to 50 vided at the upper end of the eccentric bushing 10 and of
the lower parts of the tappet which are operatively con
the toothed rack 13 suitably supported within the housing
nected with the cam, the pivotal movement may take place
11. The linear movements of the toothed rack 13 take
in an advantageous manner by means of an arm pref—
place thereby essentially in a direction perpendicular‘ to
erably forming simultaneously the bushing guide means
55 the plane of the drawing of FIGURE 1.
which is acted upon by a rotatable eccentric, cam or the
like and by a lever operatively connected therewith.
Accordingly, it is ‘an object of the present invention to
provide an adjusting mechanism for selectively adjusting
the timing point of injection for a fuel injection system,
especially for internal combustion engines, which obviates
the disadvantages of the prior art devices.
It is another object of the present invention to provide
an adjusting mechanism for adjusting the timing of the
The adjusting operation of the timing of the injection
point takes place in the embodiment of FIGURE 1 as fol
The control magnitude is transmitted by means of the
toothed rack 13 by displacing the same in the longitudinal
direction thereof. Since the toothed rack 13' is in meshing
engagement with the gear rim 12, a rotation of the eccen
injection point of an injection pump provided with a
tric bushing 10 is caused by linear displacement of the
cam shaft drive means and a tappet which considerably 65 toothed rack 13. With a rotation of the eccentric bushing
reduces the number of parts necessary in the device, is
10, the center axis of the eccentric bore of the ‘bushing
simpler in construction ‘as well as less expensive in manu
10 moves from the initial position thereof into a position
facture and assembly.
displaced with respect to the axis 14 of the cam shaft.
Still another object of the present invention resides in
The ‘bushing y together with the inner parts thereof and
the provision of an adjusting mechanism of the type de
therewith also‘ the tappet 5 itself thereby move toward the
scribed hereinabove for selectively adjusting the timing of
right or left, as viewed in FIGURE 1, upon movement of
the eccentric bore in bushing 16‘ caused by rotation.
in accordance with the present invention, it is understood '
that the same is not limited thereto but is susceptible of
The displacement components of the tappet 5 perpendic
ularly to the axis 14 of the cam shaft is indicated in FIG
URE 1, for example, by the distantce 15.
_ If the axis17 of the roller member 72 is disposed exactly
vertically above the axis 14 of the cam shaft, then the
tappet 5 assumes the highest position thereof, i.e. its upper
dead-center position when the highest point or peak 16 of ‘
thecam 1 is also disposed exactly vertically above the 10
'many changes and modi?cations within the spirit and scope
of the present invention.
For example, the possibility of moving the tappet guide
means which constitutes the principal basic concept of the
axis 14.
may be provided which move the tappet guide means or
present invention may also be applied to any other suitable
manner of construction different from that shown in con
nection with the embodiments of FIGURES 1 and 2. For
example, toothed racks, worm gear drives and the like
the tappet itself into different positions with respect to the
The dis
placement of the guide means for the tappet or of the tap
‘ If now the tappet, 5 is displaced toward the left by an
amount or dimensions 15 (FIGURE 1) by rotation of the
, cam shaft axis Within a predetermined range.
eccentric bushing 18, then the upper dead-center position
thereof, if the direction of rotation of the cam 1 is assumed 15 pet itself thereby takes place advantageously, preferably
in a direction perpendicular to the cam shaft axis.
to be in the direction of arrow 3, is advanced. Of course,
Thus, it is quite obvious that the present invention is
the time period of advance is dependent on the rotation
not limited to the two embodiments illustrated herein
of the eccentric bushing 10. ‘By thus advancing the top
but is susceptible of many changes and modi?cations
dead-center position of the tappet 5, an earlier injection
within the spirit and scope of the present invention and
of the fuel is achieved.
i In the embodhnent according to FIGURE 2, the same
,we, therefore, do not wish to be limited to the details shown
conditions exist with respect'to thedrive elements for the
. and described herein but intend to cover all such changes
tappet 5' as exist in‘co'nnection with the embodiment of
FIGURE 1. As in the embodiment of FIGURE 1, the:
and modi?cations as are encompassed by the scope’ of the
appended claims.
‘ roller member 2 of the embodiment of ‘FiGURE 2 also
runs alongthe surface 4 of the cam 11. In the normal or
We claim:
1. An adjusting mechanism for adjusting the time of
center position, the tappet .5 is in the upper dead-center
' the injection point for injection pumps comprising tappet
position thereof when the highest point or peak 16 of the
means, cam means for driving said tappet means, and guide
means for adjnsta-bly guiding said tappet means within
cam llis ‘disposed vertically above ‘the axis 14 of the cam
30 said mechanism to’ move said tappet means essentially
A'displacement of the roller member 2 from the normal
perpendicularly to the axis of said cam means, said guide
means including an eccentric bushing rotatably supported
or center position thereof is obtained, in FIGURE 2, by
pivotal movement of the entire tappet guide means about
within said mechanism, whereby said tappet guide means
the point '18. Point 18 thereby represents the effective
pivot axis, indicated in FIGURE 2 by a small circle. The
is laterally adjusted by rotation of said eccentric bushing.
2. An adjusting mechanism according to claim 1, fur
entirety of the tappet guide means consists of an arm 20
ther comprising worm gear drive means operativeiy con
and‘of a bushing 19 which is provided on the inside thereof
nected with said guide means for adjustably moving said
tappet means essentially perpendicularly to said axis within
a predetermined range into any desired positions.
with the cylindrically-shaped sliding'sur'face for the guide
bushing 8 of the tappet 5. The bushing 19 is inserted
into the housing 11 with plentiful play.
3.‘ An‘adjusting mechanism according to claim 1, fur
“The'totality of parts constituting the tappet and tappet
ther comprising a toothed rack and gear means at said’
eccentric bushing in meshing engagement with said toothed
. guide means is pivoted about the pivot axis 18 by an ec
rack to thereby rotate said bushing by linear displacement
centric 121 corresponding to the double arrows 22 and 23.
The eccentric 21 itself is provided‘with a lever 24 which is
of said rack. ‘
vadapted to be moved corresponding to the double arrow 45
4. An adjusting mechanism for adjusting the time of
25 and therewith leads by adjustment thereof to the rota‘
the injection point for injection pumps used with internal
tion of the parts '19 and 29 which are integral with each
combustion engines, comprising a’ relatively ‘stationary
, part, an eccentric bushing'rotatably supported within said
other. In order to assure continuous abutment of the
arm 20 against the eccentric '21, the arm 20 is spring
eccentric part, a relatively ?xed bushing within said eccen
loaded' on the side thereof opposite the side of eccentric 50 tric bushingptappet means including a bearing bushing
slidingly received within said'relatively ?xed bushing, cam
- ‘The displacements of the axis 17 of the roller member 2
means, a roller member in operative engagement with said
corresponding to the double arrow 23 lead to an advancing
or retarding ofthe time point of the injection, for the rea
> cam means, support means secured to said bearing bushing
for supporting said roller member on said tappet means,
said eccentric bushing being provided with gear means,
' sons already mentioned and explainedf'in connection with
the embodiment of FIGURE 1 in which the tappet 5 as
and means 'in meshing engagement with said gear means
sumes the upper dead-center position thereof and there
for adjustably rotating said eccentric bushing to thereby
1 adjust the injection point of the injection pump.
with eifects the injection of the fuel. '
The pivotal movements of the axis 17 of the roller mem- ‘
her 2 corresponding to the double arrow 23, therefore, 60
References Cited in the ?le of this patent
have the same’ control effects as the essentially horizontal
displacements of the tappet ‘guide means according to the
embodiment of FIGURE '1,’ the magnitude of which was
indicated in FIGURE 1, for example, by the dimension 15.
i 'While we have shown and described two'embodiments
Franks __; _______ __,_____ Sept. 1,, .1936
Scott ________ r. _______ _._'Nov. 7,’ 1939
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