close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2119096

код для вставки
May 31, ‘1938.
A. B. BUCKLEY
_
2,119,096
TAPPET MECHANISM
Filed March 23, 1957
4 Sheets-Sheet l
7
’
May 31, 1938.
A. B. BUCKLEY
2,119,096
TAPPET MECHANISM
Filed March 23, 1937
4 SheetS-I-Sheet 5
May 31, 1938.
A. B. BUCKLEY
2,119,096
TAPPET MECHANISM
Filed March 23, 1937
5%
4 Sheets-Sheet 4
129-11
Patented May 31, 1938
2,119,096‘
UNITED STATES
PATENT OFFICE
2,119,096
T’APPET MECHANISM
Arthur Burton Buckley, Oarshalton, England
Application March 23, 1937, Serial No. 132,469
In Great Britain October 19, 1936
12 Claims.‘ (Cl. 123—90)
Figure 6 is a section on the line 6—6 of Fig
This invention relates to tappet mechanism,
particularly for the valve gear of internal com
bustion engines. More speci?cally, the invention
is concerned with self-adjusting tappets of the
5 type (hereinafter referred to as the type de
scribed) comprising a distance piece which is
adapted automatically to extend with respect to
the tappet body on which it is mounted to take
up play, due to wear or other causes, in the tap
10 pet mechanism.
According to this invention a non-tappet
actuated means is provided for controlling the op
eration of the distance piece. By this means
the possibility of over-action of the self-adjusting
15 distance piece due to vibrations in the tappet
actuated mechanism is prevented.
The non-tappet-actuated means for control
ling the distance piece may take many different
forms. For example, it may comprise a releas
20 able spring device arranged so as normally to act
on the distance piece to restrain self-adjust
' ment, or a locking and unlocking device ar
ranged to lock together and to release the tappet
body and the self-adjusting distance piece.
In tappets wherein extension of the distance
piece is effected by relative rotational move
ment between it and the tappet body, of which
two relatively rotatable parts one is incapable of
being rotated, the said controlling means may
30 be a locking and unlocking device acting on the
other of said relatively rotatable parts. Alter
natively, when both of said relatively rotatable
parts are capable of being rotated, two locking
and unlocking devices may be provided acting
25
35 one on each of said parts.
Constructions in accordance with this inven
tion are shown as examples on the accompany
ing drawings in which:—
Figure 1 is a sectional elevation of a tappet
4O with a self-adjusting distance piece mounted
thereon,
4 01
Figure 2 is a similar view of a modi?cation of
the construction of Figure 1,
Figure 3 is a sectional elevation showing the
self-adjusting distance piece of Figure 1 applied
to a poppet valve of an internal combustion en
gine and provided with one form of controlling
means, and
50
Figure 4 is a section on the line 4-—4 of Fig
ure 3,
Figure 5 is a sectional elevation showing the
self-adjusting distance piece of Figure 2 applied
to a poppet valve of an internal combustion en-,
55 gine and another form of controlling means,
ure 5, and
Figure 7 is a section on the line ‘|—'| of Fig
ure 6,
Figure 8 is an elevation of a modi?ed‘ form
of the controlling means shown in Figures 5, 6
and_7,
Figure 9 is an elevation at rightv angles to
Figure 8, and
Figure 10 is a detail view of the controlling 10
means,
>
Figure 11 is a sectional elevation showing the
tappet and self-adjusting distance piece of Fig
ure 2 applied to the operating gear of an over
head valve with a further form of controlling 15
means, and
Figure 12 is a section on the line |2—|2 of
Figure 11,
Figure 13 is a sectional elevation showing the
controlling means of Figures 11 and 12 applied to
a tappet for a poppet valve,
Figure l4 is a detail view showing a modi?
cation, of the construction of Figure 13, and
Figure 15' is a sectional elevation showing. a
modi?cation of the construction shown in Figure
2 with a controlling means applied thereto.
' Like reference numerals indicate like parts
throughout. _
In the construction shown in Figure 1, the
self-adjusting distance piece comprises a body 20
which is‘ screwed onto the upper screwthreaded
end of a stem portion 2| for insertion as shown
into a bore 22 in the upper end of a tappet body
23. The stem portion 2| has midway between
its ends a conical shoulder which seats in the
upper end of the tappet body so as to locate
the stem portion in the correct position in the
tappet. Alternatively, the stem portion may be
integral with the tappet. The body 20 of the dis
tance piece has in its bottom face a recess 24
in which a helical loading spring 25 of opposite
hand to the screwthread on the stem portion 2|
is accommodated. The spring 25 is anchored at
one end to the body 20 and at'the other end to
45
the stem portion 2| and so tends always to un
screw the body from the stem portion. Screwed
on to the outside of the body is a cap 26 having
within it a loose disc 21 which constitutes a yield
able head member and is pressed upwardly
against the top of the cap by a conical-helical
spring 28 interposed between the body 20 and
the head member. An aperture 29 is provided
in the top of the cap to permit a poppet valve
stem 30 shown in chain lines in Figure 1, or other
55
2
2,119,096
member to be actuated by the tappet, to engage
the head member 21.
In assembling the parts of the distance piece,
the cap 26 is adjusted on the body 20 so that the
clearance 3! between the. latter and the head
member 2'! is a predetermined amount, say the
usual tappet clearance of about .004" plus the
thickness of the conical-helical spring 28 when
fully compressed. The cap 26‘ is then ?xed in
its adjusted position on the body 20 by a pin
32. On the drawings, the clearance 3| is shown
exaggerated for clarity.
~
When clearance between the distance piece and
the valve stem 30 is being taken up, the body 20'
15 and the head member 21 move as a unit under the
action of the loading spring 25, but if extension
of the valve stem occurs the head member 21 will
be depressed by the valve stem against the action
of the spring 28 while the body 20 remains sta
20 tionary thus still permitting the valve to close
properly.
_
I
V
In the construction shown in Figure 2, the body
20 has an integral screwthreaded stem portion 2|
device arranged to lock together and release the
tappet body and the self-adjusting distance piece
and it comprises a U-shaped clip 42 made from
?at spring steel. The cross member of the clip
has in it a rectangular slot 43 and ?ts over ?ats
44 formed on opposite sides of the upper end of
the tappet body 23. The side limbs of the clip
are each bent inwardly so as to bear on a lower 10
?ange 45 on the cap 26, and the‘ upper end of
each side limb is reduced in width to provide a
?nger 46 for engagement between teeth provided
around‘ an upper ?ange 41 on the cap 26. The
distance piece is thus locked against the action of 15
its: loading spring 25 which is not shown in Fig
ures 5,6, and 7. The clip 42 is prevented from
being accidentally dislodged from the distance
piece due to vibration, when the engine is work
ing, by’ the lower ?ange 45 on the cap 26.
20
To release the clip 42 to permit the distance
piece to take up clearance, the side limbs of the
clip have to be forced'apart to disengage the ?n
which is screwed into the bore 22 of the tappet.
gers 46 from the teeth on the ?ange 41. A clip
Theloading spring 25 is a torsion spring which
is attached at its upper end to the lower end
releasing device may be provided for this pur 25
pose, said device being preferably arranged so as
of the stem portion 2| and at its lower end to a
to permit it to be operated from outside the en
plug 33 screwed into the bottom; of the bore 722.
gine casing.
The screwthreaded bore 22' is longer. than the
30 stem portion 2| and when mounting the self
adjusting distance piece in the tappet 23, the
plug 33 is ?rst screwed to the bottom of the bore
22 and then the stem portion 2| is screwed into
said bore. The latter operation winds up the
loading spring 25 ‘so that it tends to cause the
stem portion to unscrew from the tappet with the
result that the distance piece extends as a‘ unit
relatively to the tappet to take up tappetclear
ance instead of thebody 20 moving relatively to
the stem portion for this purpose as in the con
struction shown in Figure l.
._
Several alternative‘forms of ‘controlling means
for the purpose mentioned above which may be
used with either of the self-adjusting distance
pieces shown in Figures 1 and 2 will now be de
scribed.
.
The controlling means shown in Figures 3 and 4
is a spring device arranged to counteract the
action of the loading spring 25. This spring de—
vice comprises a Z-shaped spring 34>formed by
bending a strip of sheet metal. The lower limb
of the spring which is shorter than the upper
limb is ?xed by a screw to a ?ange 35 onrthe
tappet guide 36, and the upper limb presses down
55 wardly on the top of the cap 26- with sui?cient
force to prevent the latter from rotating. The
free end of the said upper limb is forked to ac
commodate the stem 30 of the poppetvalve 38 and
to permit it to be withdrawn laterally from con
60 tact with the cap 26 to release the latter which is
then‘ free to be acted upon by the loading
spring 25.
.
It will be appreciated that the controlling
-
In the modi?cation shown in Figures 8, 9 and
10 of the foregoing construction, the cap 26 has 30
around the top a plain ?ange 48 and the side
limbs of the clip 42 are bent inwardly and have
their. upper ends bent downwardly, see especial
ly Figure 10. The side limbs are also cut so as to
provide tongues 49 which are also bent inwardly. 35
When the clip is sprung on to the self-adjusting
distance piece, the side limbs assume a vertical
position and their downwardly bent upper ends
bear on top of the ?ange 48 as shown in Figure
9; The tongues 49 then press against opposite 40
sides of the cap 26 which is thus held by friction
against rotation due to the action of the loading
spring 25.‘ As in the construction of Figures 5, 6
and‘ 7, thecross member of the clip has in it a
rectangular slot and ?ts over the flats 44 formed
on opposite sides of the upper end of the tappet
body 23.
-
In constructions wherein that part of the self
adjusting distance piece which has to be locked to
prevent extension of the distance piece is a ro 50
tatable part, the controlling means may be a
locking and unlocking device comprising a rotat
able member which is constrained to rotate with
said rotatable part, a split ring encircling the
rotatable member, and a locking screw acting 55
through said ring to prevent rotation of the ro
tatable member. Such a construction is shown
in F'gures 11‘ and 12. In this construction, the
head, member 21 has an integral shank 50 of
rectangular cross section which on opposite sides (ll)
?ts a rectangular opening 5| in the top of the
cap 26, see also Figure 2. Thus relative rotation
between the cap 26 and the shank 50 is prevented.
means must be released to'_permit the self-‘ad'
The shank 50 reaches through said opening and is
justing distance piece to take up clearance. To
this end, an eye 39 is provided on the cross limb
connected by a pin joint to the lower end of a
push rod 52 whereof the upper end is connected
of the Z-shaped spring 34 for the‘ attachment of
a link to permit operation of the sprin’glfromi a
by a similar joint to the rocking lever 53 for
point outside the engine casing 40. To give’ ac-‘
70
The controlling means shown in Figures 5, 6,
and 7 is in the form of a locking and unlocking
cess to the eye 39, an opening closed by a cover 4|
is provided in the engine casing.
In practice, the controlling means will be re
leased periodically to allow the self-adjusting dis;
tance piece automatically to take up any clear
ance due to wear after which it will be reset,
operating the valve 54. The upper end of the
tappet body 23 has on opposite sides, ?ats 55
which ?t’ a correspondingly shaped hole 56?in a
circular bearing member 51' mounted so as'tdibé
able to rotate in a recess formed in the tappet
guide 36. The bearing member has a peripheral
groove 58 which is engaged by a locking screw 59
whereby the bearing member is retained in the 15
3
2,119,096
recess in the tappet guide and can be held against
rotation. A split wearing ring 60 is housed in the
groove 58 and serves to transmit the pressure of
the locking screw 59 to the bearing member 51
and also to protect the latter from being damaged
by the screw. When the screw 59 is tightened
the tappet body 23 is locked against rotation
and rotation of the distance piece in the tappet
is prevented by its connection with the push rod
52. The distance piece is thus restrained from
self-adjustment.
In order to permit self-adjustment, the locking
screw 59 is slackened to allow the tappet body 23
and the bearing member 51 to turn together and
15 the engine is turned by hand or caused to run
slowly under its own power. Should there be
any clearance or slackness in any of the joints
of the valve gear between the valve 55 and the
cam 6| for operating the tappet, the tappet body
will be caused to turn by the action of the load
ing spring 25 which is omitted from Figure 11.
This results in the self-adjusting piece being
extended to take up said clearance or slackness.
The screw 59 is then again tightened to re?x the
25 distance piece. The head of the locking screw
59 is situated outside the engine casing 40 to
permit the screw to be easily operated.
The locking and unlocking device shown in
Figures 11 and 12 with slight modi?cations may
30 be applied to a tappet for a poppet valve as
shown in Figure 13.
In this case, the cap 26 of
the self-adjusting distance piece is provided with
?ats 62 which ?t and slide within the rectangular
hole 55 (see Figure 12) in the bearing member
51, and the tappet body is provided with ?ats 53
on opposite sides which engage corresponding
?ats in the tappet guide so as to prevent rota
tion of the tappet body while permitting it to
slide freely endwise in its guide. When the look
ing screw 59 is tightened, extension of the self
adjusting distance piece is prevented but when
said screw is slackened, the distance piece is
free to be rotated by the action of the loading
spring 25 (not shown in Figure 13) and carry
round with it the bearing member 51. As the
latter is prevented from moving in the direction
of its axis of rotation by the locking screw 59,
the self-adjusting distance piece is constrained
to slide endwise in the bearing member to take
up any tappet clearance. Instead of providing
the ?ats 63 on the tappet body 23 for prevent
ing rotation of the latter, a second locking and
unlocking device similar to that described with
reference to Figures 11 and 12 may be applied to
the upper end of the tappet body 23 as shown
55
in Figure 14.
In the construction shown in Figure 15, the
stem portion 2! is screwed into a sleeve 64 and is
?xed therein by a pin 65 to prevent relative
movement between the body 29 and the sleeve
64. The upper end of said sleeve is screwed into
the upper end of the bore 22 of the tappet body
23, and the lower end of the sleeve is reduced in
65
diameter to provide an extension 66 which ?ts
snugly into a correspondingly reduced plain por
10
15
20
25
15 may be used instead of the screwthreaded
plug in the construction of Figure 2 and any of
the devices for controlling the operation of the
distance piece may be used with any of the self
adjusting distance pieces described above.
I claim:—
1. The combination with a self-adjusting dis
tance piece for tappet mechanism and compris
ing a body adapted when mounted on a tappet 40
to extend with respect to the tappet to take up
tappet clearance and a loading spring for effect
ing said extension, of a locking and unlocking
device for locking together and releasing the tap
pet and the self-adjusting distance piece.
2. The combination with a self-adjusting dis
tance piece for tappet mechanism and compris
ing a body for mounting on a tappet so as to
be capable of rotating relatively to the tappet
and adapted when in use to extend with respect 50
to the tappet due to said relative rotation and a
loading spring for eiiecting the relative rotation,
of a locking and unlocking device for locking
that one of the aforesaid relatively rotatable
parts which has to be locked against rotation to 55
prevent extension of the distance piece and for
releasing said rotatable part.
~
3. The combination of parts claimed in claim
2, wherein the locking and unlocking device com
prises a rotatable member which is constrained 60
to rotate with said rotatable part, a split ring
encircling the rotatable member, and a locking
screw acting through said ring to prevent rota-'
tion of the rotatable member.
4. In a tappet, the combination with a tappet 65
tion of the bore in the tappet body. The plug
body of a self~adjusting distance piece compris
33 is a loose ?t in said reduced portion of the
bore 22 and is held against rotation therein by a
ing a body having a stem portion, a sleeve for
screwing into a screwthreaded bore in the tappet
body, in which sleeve said stem portion is
mounted so as to be incapable of movement rel 70
atively to the sleeve, the inner end of which bore
is plain and of lesser diameter than the screw
threaded portion thereof, an extension on said
removable pin 61. The stem portion 2! and the
plug 33 are provided with opposed forked lugs
58, 59 respectively to which the ends of the load
ing spring 25 are attached. A washer 10 held
in position on the top face of the tappet guide
36 overlaps the bearing member 51 of the locking
75 and unlocking device and serves to retain said
70
block in its recess in the tappet guide while per
mitting rotation of the bearing member when the
screw 59 is released. Rotation of the distance
piece including the sleeve 64 is prevented because
the shank 50 of the head member ?ts, in the
manner described with reference to Figure 2, the
rectangular opening 5| in the cap 26 and is con
nected to a push rod 52 (not shown in Figure 15).
With the form of plug 33 shown in Figure 15,
the overall length of the tappet body and dis
tance piece can be adjusted by hand to a greater
extent than is possible with the construction
shown in Figure 2 without unduly increasing the
tension of the loading spring 25 inasmuch as
when the pin 61 is removed, the plug is free to
rotate on its seating in the bottom of the bore 22
while the sleeve 64 is being screwed into the tap
pet thus relieving the spring of excessive tor
sional strain. This is an advantage because it
reduces the degree of accuracy required when
initially machining the lengths of the various
parts of the valve gear and this generally results
in lower production costs. Further as the exten
sion 66 of the sleeve 64 slides within the reduced
part of the bore 22 it imparts longitudinal steadi
ness to the assembly independently of the fit of
the screwthreaded portion of the sleeve in the
upper end of said bore.
The invention is not restricted to the speci?c
constructional details shown on the drawings.
For example, the form of plug shown in Figure
sleeve ?tting snugly in the inner end of the bore,
a plug which is a loose ?t within the inner end 75
2,119,090
of the bore, a removable pin for holding the plug
in position in the bore, and a torsion loading
spring for effecting extension of the distance
piece anchored at its ends to the aforesaid stem
Cu portion and to the plug respectively.
5. The combination with a self-adjusting dis
tance piece for tappet mechanism adapted when
mounted on a tappet body to extend with respect
to said body to take up tappet clearance and a
10 loading spring for effecting said extension, of a
manually operable means for locking the distance
piece against movement under the action of the
loading spring.
6. The combination with a self-adjusting dis
tance piece for tappet mechanism adapted when
mounted on a tappet body to extend with respect
to said body to take up tappet clearance and a
loading spring for effecting said extension, of a
releasable spring device arranged so as normally
to act on the distance piece in opposition to the
loading spring to render the latter ineffectual.
'7. The combination of a tappet body, a self
adjusting distance piece mounted on the tappet
body and adapted automatically to extend in re
lation thereto, and locking means operated inde
pendently of the operation of the tappet for lock
ing the distance piece against movement under
the action of the loading spring.
8. The combination of a tappet body, a self
adjusting distance piece mounted on the tappet
body, a torsion loading spring tending to cause
the distance piece to extend with respect to the
tappet body, and a locking device that is operated
independently of the operation of the tappet and
acts normally on the distance piece to lock the
latter against the action of the loading spring.
9. The combination of a tappet body, a self
adjusting distance piece mounted on the tappet
body and adapted to extend in relation thereto,
which extension is effected by relative rotational
movement between the tappet body and the dis
tance piece, of which two relatively rotatable
parts‘ one is'held so as to be incapable of being
rotated, means for causing rotation of the other
of said relatively rotatable parts, and a locking
and unlocking device acting on said other rotat 10
able part.
10. The combination of a tappet body, a self
adjusting distance piece mounted on the tappet
body and adapted to extend in relation thereto,
which extension is effected by relative rotational
movement between the tappet body and the dis
tance piece, both of which relatively rotatable
parts are capable of being rotated, and two lock
ing and unlocking devices acting one on each of
said relatively rotatable parts.
20
11. The combination of parts claimed in claim
9, wherein said locking and unlocking device
comprises a bearing member which is mounted on
the rotatable part of said relatively rotatable
parts so as'to rotate therewith, and securing 25
means for preventing rotation of said bearing
member.
12. The combination of parts claimed in claim
10, wherein each of said locking and unlocking
devices comprises a bearing member which is 30
mounted on the rotatable part so as to rotate
therewith, and securing means for preventing
rotation of said bearing member.
ARTHUR BURTON BUCKLEY.
35
Документ
Категория
Без категории
Просмотров
0
Размер файла
793 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа