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Патент USA US2410404

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Patented Nolv.‘5, 1946
2,410,404 `
UNITED sTATÀEs .PATENT .oF-Fics
2.410.404
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VALVE
J. D. Buchanan, Burbank, Calif.
Application November 15, 1943, Serial No. 510,389
`
4 claim,.-
(ol. 251-76)
The invention relates to a valve and particu
shell 8 by suitable means such as screws I2.
The cap I 0 is imperforate and a sealing ring I3
is arranged between cap I0 and the left end of
-larly to a valve for controlling high pressure such
as 1,000 pounds per square inch and more, as
employed in modern hydraulics, and wherein the
valve head mustñt on its seat with a very close
tolerance to prevent leakage at such pressures.
It has heretofore been proposed to employ a
valve head which is integral with a valve stem,
and this necessitates that thebore in which the
`valve stem slides with respect to the valve seat
must be coaxial'therewith` to the same closel
tolerance as that required between the valve head
and its seat. This increases the cost of making
such valves and in working to these close toler
ances for all the working parts, as stated.
. shell 9 to prevent leakage. Fitting in the shell
9 is a hollow cylindrical valve seat Il having e.
cooperating cylindrical valve head I5 ’mounted
on resilient ring seals I8 and Il on the valve
stem d. Fitting in the shell 9 against the left
end of the valve seat I4 is a bearing block I8
having a cylindrical bore I8 in which the piston '
20 slidingly ñts. The piston 20 has a ring seal
2i and it is loosely mounted on- a reduced portion
of the valve stem 8 indicated at 22. The left end
of the valve stem portion 22 is threaded as in- ’
dlcated at 23 to receive a nut 20 which clamps
the piston 2| against the valve h'ead I5,»urglng ~
the latter against a piston 25 which is fixed on
An object of the present invention is to reduce
the cost 'and simplify the manufacture of such
V valves while maintaining the desired close toler
the valve stem 0. Piston 26 has a sealing ring
ance'between the valve head and its seat, while
20 and it slidingly ñtsin a bore' 27 the same size
permitting slight eccentricity between the valve 20 as the bore I0, and arranged in the bearing block
seat and the valve stem bearing. '
28 at the right end of the valve seat it.
\
'I'his is accomplished by not making the valve
The nut 20 is suitably locked in place with
head integral with the valve stem, but instead by
enough clearance between the valve head it and
supporting it on the stem with provision-for lat
the pistons 20 and 20 to permit valve head i5 to
eral displacement of the valve head with respect 25 displace laterally with respect to valve stem 0.
to the valve stem. In this way the valve'stem and
This clearance may be of the order of one
valve head need not be exactly coaxial, while
thousandth oi> an inch, a clearance too large for
nevertheless an accurate fit between the valve
the fit between the valve head I5 and its seat it.
` head and its seat is possible.
One or both of the seat it and the valve head
For further details of the invention, reference 30 i5 is or are hardened, steel, groundand lapped
may be made to the drawingwherein:
'
Fig. 1 is a schematic showing of a well known
valve system employing
surfaces, chromium plated and ñtting together
witllîi a very close tolerance such as .0001 or .0002
the improved valve of ,
inc
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'
this invention.
Pistons 20 and 2E are preferably oi’ steel, and
Fig. 2 is a longitudinal sectional View of the 35 their cooperating 'slide bearings in the blocks i8
valve of this invention.
and 20 are preferably of bronze.
l
. `Fig. 3 is a sectional view on line 3_3 of Fig. 2,
looking in the direction of the arrows.
Valve head it is provided with three annular
,
grooves such as 20, each having a width greater _
Referring in detail to the drawing, the valve
-of this invention, generally indicated at i, may
than the four ribs such as 30 in the valve seat It,
whereby the valve head it, by means of the valve
stem 0, may be moved to the left, or to the right,
from the neutral position shown, to control the
be employed to control a high pressure ñuid hav
ing a pressure of 1,000 pounds per square inch or
more in the supply pipe 2. to move the piston `3
in one direction or another, as is well known.
For this purpose, the valve i, as usual, is also pro
vided with two outlet lines lâ and 5 communicat
45
reciprocation of piston 3 in an obvious manner.
Valve head i5 is maintained normally in the
neutral position shown, ywherein the pressure in
- inlet pipe 2 is not communicated to either outlet
ing with opposite sides of the piston 3 and with
@l or 0, by means of a compression spring 3| which
two return lines 6 and l. The piston 3 may be
_bears at its right end against a washer 32 which
connected to any suitable load to be reciprocated
in response to the sliding movement of the valve 50 rits around stem 3 and bears against a shoulder
stem 8.
'
>
'
a3 on the inside .of cap ii. Cap ii at its outer
As shown in Figs. 2 and 3, a valve I has a casing
comprising a cylindrical shell 9 having end caps
end has a suitable bearing @el for a yvalve stem
extension 30 secured to the valve stem ß by a
lock pin 00. The other end oi' spring iii bears
i0 and il, all of which may be _made of aluI
minum. Cap i0 is secured to the left end of the 55 against a washer ¿il which rides on the stem 0 and
4
bears against the right end of the bearing
of said valve head on said valve stem, and 're
block 28.;
silient sealing means supporting said valve head
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Cap III‘has an annular extension I0' which fits
in. the shell 8, and cap I I has a similar extension
II', which bears against the outer ends of blocks
I8 and 28 respectively to compress them >tightly
against the ends of the valve seat Il; Cap Il
for lateral displacement on said valve stem,
whereby said valve head ñts said valve seat with
a closer tolerance than the tolerance of the ec
centricity between said valve seat and said valve
stem> bearing.
has screws 45.
2. A ~valve comprising the combination of a
'I'he valve seat It has live spaced annular
hollow cylindrical valve seat having inlet, outlet
grooves or passageways 44, with one of the annu 10 and return ports, a cylindrical valve head slidably
lar ribs or valve portions 3u between adjacent
iltting in said seat with a close tolerance, a valve
grooves M. The two outer grooves M communi
stem in said valve head, a piston head on said
cate with the return pipes 8 and 1 respectively,
The central groove 44 communicates with the
inlet 2, and the- other two grooves 44 are con
, valve stem at each end of said valve head, means
for retaining said-valve head between said piston
15 heads witha tolerance permitting lateral move
ment of said valve head on said valve stem, spaced
nected to the `outlets l and 5. In order to cushion
resilient ring seals cn said valve stem supporting
the movement of valve I5, a restricted outlet 38
said valve head for lateral displacement, and a
and 39 may be provided between each end of
bearing at each end of said valve head, each of
valve I5 and the adjacent return 1 and 8 re
spectively. With the valve I5 in neutral position 20 said bearings having a bore in which one oi said
piston heads slidingly iìts.
as shown in Fig. 2, spaces 40 and 4I exist between
3. A valve comprising the combination oi’ a
the left and right ends of valve head I5 and the
adjacent bearing blocks IB and 28 respectively.
hollow cylindrical valve seat having inlet, outlet
and return ports, a cylindrical valve head slidably
When valve stem is moved to the right, space l0
increases in size until the left end of valve head 25 fitting in said seat with a close tolerance, a valve
stem in said valve head, resilient sealing means
I5 uncovers the groove M connected to return 1,
' supporting said valve head on said valve stem, a
whereupon iluid flows from return 1 into space
fixed piston on said valve stem at one end of said
IIJ. Space 40 communicates with restricted out
valve head, a second piston slidably iitting on
let 38 through an annular groove 42 in the bearing
block I8, and a similar groove 43 is providedv in 30 said valve stem at the other end of said valve
head, means for retaining said second piston in
the bearing block 28. When the valve head I5
position with said valve head between said pistons
is later moved to the left, its movement is cush
with a tolerance permitting lateral displacement
ioned, as the ñuld in space 40 must pass through
of said valve head with respect to said valve
the restricted outlet 38. When valve head I5 is
moved to the left, the right end of valve head 35 stem, and spaced bearings each having a. bore in
' I5 uncovers the groove 44 connected to return 6
which one ofsaid pistons slidably flts,~whereby
the coaxiality of said bores with respect to said
to admit ñuid to space 4I. Restricted outlet 39
valve seat may have a greater tolerance than the
cushions the movement ofvvalve head I5 to the
tolerance with which said valve head ñts said
right. Hence valve I5 is cushioned in both direc
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v
tions.
40 valve seat.
4. A valve comprising the combination of a
It will be apparent that the cost oi' constructing
hollow cylindrical valve seat, a cylindrical valve
the valve has been reduced through eliminating
head slidablyfitting in said seat with a close
the necessity for machining the interior of valve
tolerance, said valve head having a cylindrical
seat Il to be exactly coaxial with the valve stem
bearings in the _blocks I8 and 28, by reason of 45 bore, a valve stem extending through said bore
and smaller in size than said bore, resilient seal
the'fact that the valve head I5 in effect iloats
ing means in the bore of said valve head and ar
on the ring seal I5 and I1, and hence the valve
ranged between said valve head and said valve
head I5 may very accurately iit its seat I4 even
stem, said sealing means supporting said valve
though there is substantial eccentricity between
the valve stem 8 (or the valve stem bearings in 50 head for ñoating movement on said valve stem,
a bearing at each end of said valve head support
blocks I8 and 28) and the bore of valve seat I4.
ing said valve stem for sliding movement, spaced
It will be apparent that the valve may be used
abutment means on said valve stem at the op
for either high or low pressures, and that various
posite ends of said valve head for retaining said
modifications may be made in the invention with
out departing from the spirit of the followingy 55 valve head in position on said valve stem with
a tolerance permitting said valve head to iit said
claims. For example, instead of using two seal
seat with a close tolerance even though the axis
ing rings I8 and I1, only one central sealing ring
of said valve seat is offset and substantially paral
Vmay be used.
lel to the axis of said valve stem and even though
I claim:
`
1. A valve comprising the combination of a 60 the axis of said valve seat intersects the axis
of said valve stem at a point beyond said valve
valve stem, a bearing therefor, a hollow cylindri
head, whereby the coaxiality of said valve stem
cal valve seat, said bearing and said seat being
bearings with respect to said valve seat may have
relatively eccentric, a. cylindrical -valve head fit
a greater tolerance than the tolerance with which ting said seat with. close tolerance, abutment
means on said valve stem for imparting valve 65 said valve head ñts said valve seat.
opening and closing movement to said valve head
with a tolerance permitting lateral displacement
J. D. BUCHANAN.
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