[0001] The present invention relates to valves in which relative rotation of concentrically
mounted rings is used to effect opening and closure of the valve; more particularly,
it is related to valves wherein the concentrically mounted rings carry one or more
flexible sleeves.
[0002] Such valves are typically used for controlling the flow of particulate material from
a hopper or other container.
[0003] In a known form of a valve of this type, the flexible sleeve is secured at each end
to a circumferential ring. The ring at one end of the sleeve is secured by means of
a first clamping ring in a recess in a first casting having an annular mounting flange
which is apertured to enable it to be bolted to a corresponding flange around the
lower outlet of the hopper or other container. The ring at the other end of the flexible
sleeve is disposed in a recess in a second casting which is mounted on the underside
of the first casting so as to be rotatable relative thereto. The clamping ring at
said opposite end of the sleeve is rotatable with the second casting so that, upon
rotation of the latter relative to the first casting, for example by hand, the sleeve
can be twisted or untwisted so as to close or open, respectively, the valve.
[0004] However, this type of valve requires 180° of relative circular movement of the rings
to close the sleeve fully from its fully open position. Achieving this movement mechanically
(e.g. using a pneumatic cylinder) usually requires a complicated cable mechanism which
requires frequent adjustment to compensate for wear and cable stretch.
[0005] In accordance with the present invention, there is provided a valve comprising a
flexible sleeve having first and second axially spaced sleeve portions; first and
second coaxially disposed, relatively angularly movable rings relative to which the
first and second sleeve portions are respectively fixed; and means for mounting the
first and second rings around an opening through which the flow of material is to
be controlled by the valve; wherein the first and second rings form parts of an epicyclic
gear mechanism; and wherein means are provided for effecting angular movement of part
of the epicyclic gear mechanism between a first position corresponding to a fully
closed position of the valve and a second position corresponding to a fully open position
of the valve, said epicyclic gear mechanism producing an increased angular relative
movement of the rings for a given angular movement produced by said angular movement
effecting means.
[0006] In one embodiment, the first ring is fixed against angular movement, the epicyclic
gear mechanism comprises a carrier upon which pinion wheels are rotatably mounted,
said pinion wheels drivingly engage the first and second rings and said angular movement
effecting means can be used to move the carrier such that angular movement of the
carrier is transmitted, by cooperation of said pinion wheels with said first and second
rings, to the second ring and produces a correspondingly increased angular movement
thereof.
[0007] Preferably, at least one of said pinion wheels is toothed, the teeth engaging with
corresponding teeth on the inner surface of the first ring and the outer surface of
the second ring.
[0008] In a particularly preferred embodiment, a portion of each pinion wheel which engages
the first ring has a different diameter to a portion of each wheel which engages the
second ring so that the angular movement of the rings produced by the angular movement
effecting means is further increased. :
It is also preferred that the first ring comprises a casing and a fixed ring, the
fixed ring being fixedly connected to the casing and engaging said pinion wheels,
said first flexible sleeve portion being fixed relative to the casing.
[0009] The means for rotating the carrier is conveniently an arm attached at one end to
said carrier and at its other end to mechanical means such as the piston of a pneumatic
cylinder or a threaded screw driven by an electric motor, for providing movement of
said arm. It will be appreciated that this valve may also be manually operated either
by manually moving the arm directly or by operating a reduction means such as a manually
operated screw mechanism.
[0010] In a further embodiment the epicyclic gear mechansim comprises a plurality of pinion
wheels rotatably mounted on said mounting means and engaging said first and second
rings, said angular movement effecting means being used to move one of said rings
such that angular movement of said one of said rings is transmitted by cooperation
of said pinion wheels with said first and second rings to the other of said rings
and produces a correspondingly increased angular movement thereof.
[0011] Embodiments of the present invention will now be described, by way of example, with
reference to the accompanying drawings in which :-
Fig. 1 is a part section plan view of a valve according to a first example of the
present invention.
Fig. 2 is a half section elevation on the line A-A of Fig. 1,
Fig. 3 is a section on the line B-B of Fig. 1,
Fig. 4 is a section on the line C-C of Fig. 1,
Fig. 5 is a sectional view through part of a second example of a valve according to
the present invention,
Fig. 6 is a sectional view through part of a third example of a valve according to
the present invention, and
Fig. 7 is a sectional view through part of a fourth example of a valve according to
the present invention.
[0012] Referring now to the drawings, the valve of the present invention comprises a casing
1 having an upper and lower face la and lb, each face being defined by an inner and
outer part 40a, 40b fixed together by screws 41 located in threaded bores 42..
[0013] The casing 1 has an internally toothed fixed ring 2 firmly fixed thereto by means
of external pegs (not shown) fitted into corresponding locating holes (also not shown)
in the casing 1 and fixed ring 2 and also by means of three pairs of fixing screws
3, 3a, each pair of which is located in a respective threaded bush 4 in a respective
arcuate slot 5 in a radially outer part of the ring 2. Counterbored holes, 6, 6a are
provided in the upper and lower faces la, lb, of the casing 1 so that the heads of
the fixing screws 3, 3a are set below the surface of each respective face la, lb.
The arcuate shape of the slots 5 allows adjustment of the position of the fixed ring
2 relative to the casing 1 to account for any stretch in the valve closure member
to be described hereinafter. Such adjustment can be effected after removal of the
pegs from the locating holes. The casing 1 and the fixed ring 2 together define a
first ring.
[0014] The valve closure member is a two-part sleeve comprising a first sleeve 7 and a second
sleeve 8, each sleeve having respective first (7a, 8a) and second (7b, 8b) parts.
The free end of the first part 7a of the first sleeve 7 is positioned in a groove
10 in the upper face la of the casing 1 and is held there by retaining plate 11 and
screws 12. The free end of the first part 8a of the second sleeve 8 is similarly held
in a groove 13 in the lower face lb of the casing by a retaining plate 14 and screws
15.
[0015] A second ring 16 which is toothed on its outer periphery is provided concentrically
with the fixed ring 2 and between the portions of the upper and lower faces la, lb
of the casing where the free ends of the first parts 7a, 8a of the first and second
sleeves 7 and 8 are respectively retained. Grooves 17 and 18 are provided in the top
and bottom surfaces of the second ring 16 together with respective retaining plates
19, 20 and retaining screws 21, 22. These serve to retain the ends of the second parts
7b and 8b of the first and second sleeves 7 and 8 in the same way that the free ends
of the first parts 7a and 8a are retained in the casing. In this particular embodiment
however, only one groove 17 is used as the first and second sleeves are formed from
a single folded tube of material, the second parts 7b and 8b having common ends.
[0016] It is to be appreciated that this embodiment of the present invention will work equally
as well with the first and second sleeves 7 and 8 formed from two separate folded
tubes in which case both grooves 17 and 18 would be used to retain the free ends of
the two tubes.
[0017] Annular seals 23 are provided between respective portions of the second ring 16 and
the casing 1.
[0018] A third ring comprising upper and lower pinion support rings 24 and 25 is provided
within the casing 1 externally of the second ring 16. Between the upper and lower
pinion support rings 24 and 25 there are six equiangularly spaced bearing units 26
comprising an upper and a lower locating stud 27, 28 and a bearing bush 29, each bearing
unit 26 carrying either a toothed pinion wheel 30 or an upper and a lower idler wheel
31a, 31b. The teeth on the pinion wheel 30 engage with the teeth on the first and
second ring 2 and 16. The pairs of idler wheels 31a, 31b engage the rings 2 and 16
on non-toothed peripheral edges of the latter and serve to maintain the relative positions
of the first, second and third rings.
[0019] A handle 32 formed of an upper part 32a and a lower part 32b is attached at one end
to the respective pinion support rings 24, 25 forming the third ring, apertures being
provided in the other ends of the parts 32a, 32b to which mechanical drive means can
be attached such as a pneumatic piston and cylinder device 34. The parts 32a and 32b
of the handle 32 project through respective openings 33 provided in the casing 1 the
parts 32a and 32b passing respectively above and below the first ring 2. Movement
of the handle 32 effects rot-ation of the third ring relative to the fixed ring 2.
The total possible range of rotation of the third ring is limited by the stroke of
the pneumatic piston and cylinder device 34.
[0020] As the ring 2 is fixed, rotation of the third ring relative to the ring 2 causes
rotation of the pinion wheels 30 due to the mutual engagement of the teeth between
the pinion wheels 30 and the fixed ring 2. This induced rotation of the pinion wheels
30 is transmitted in the manner of an epicyclic gear mechanism to the second ring
16 through the engagement of the teeth provided on the pinion wheels 30 and the second
ring 16. Consequently, for a given angular displacement of the third ring, a correspondingly
increased angular displacement of the second ring 16 occurs. In the present example,
81° rotation of the third ring causes 180° rotation of the second ring 16 and so effects
closure of the valve by twisting of the first and second sleeves 7 and 8. Opening
of the valve is effected by a corresponding rotation in the opposite direction.
[0021] It will be appreciated that the amount of angular displacement of the second ring
relative to the third ring is due to the relative radii of the first and second rings
in accordance with the principles of epicyclic gearing.
[0022] In a second example, as illustrated in Fig. 5, the valve is similar to the valve
of Fig. 1 and similar parts are accorded corresponding reference numerals in the 100
series. In this example, internally toothed fixed ring 102, instead of being of one-piece
construction like ring 2, is of three-piece construction and comprises an outer ring
portion 102a and spaced upper and lower ring portions 102b and 102c, respectively
'0' ring seals 155 are provided in grooves 156 in the upper and lower surfaces of
the outer ring position 102a, and radially inward of the fixing screws and associated
structure 103 - 106. The upper and lower ring portions 102b and 102c are secured in
upper and lower stepped formations in the outer ring portion 102a by means of respective
sets of screws 150 and 151. The inner edges of the respective ring portions 102b and
102c are disposed further inwardly in the radial direction than the outer ring portion
102 and are toothed for engagement with corresponding upper and lower annular sets
of teeth 152 and 153 on pinion wheel 130. The pinion wheel 130 is also provided with
an intermediate annular set of teeth 154 which mesh with the teeth on the outer periphery
of second ring 116. The upper and lower annular sets of teeth 152 and 153 are of the
same diameter which is half of that of the intermediate annular set of teeth 154.
The valve of Fig. 5 also has a set of idler wheels (not shown) corresponding to idler
wheels 31 described above. However, in this embodiment, the idler wheels are of a
similar stepped outline to the pinion wheels 130 but without the toothing thereon.
The valve of Fig. 5 operates in a similar way to that described above except that,
as a result of the 2:1 diameter ratio of the toothing described above, an increased
angular displacement of the second ring 116 is obtained for a given rotation of the
third ring. In this embodiment, 54° rotation of the third ring gives 180° rotation
of the second ring 116.
[0023] In a third example, as illustrated in Fig. 6, the valve is similar to that shown
in Fig. 5. However, the overall diameter of the valve has been reduced by reducing
the diameter of the epicyclic gear arrangement. In Fig. 6 similar parts to that shown
in Fig. 5 are accorded corresponding reference numerals in the 200 series and certain
parts have been omitted for clarity. In this example, internally toothed, fixed ring
202 is of one-piece construction replacing the three piece construction 102a, 102b,
102c shown previously. Each face of the casing is defined by a respective single part
240. Upper and lower handle parts 232a, 232b and their respective pinion support rings
224, 225 are also integrally formed, which further serves to reduce the diameter thereof.
[0024] In an alternative embodiment of the present invention shown in Figure 7, the pinion
wheels are fixed with respect to the casing and valve closure is effected by rotation
of the outer ring. Similar parts to those shown in previous drawings are accorded
corresponding numbers in the 300 series.
[0025] Outer ring 302 is not fixed to the casing but is free to rotate and is supported
by rubbing strips 360, 361 mounted on upper and lower casing parts 340. Seals 362,
363 are also provided in the parts 340 located outwardly of the strips 360, 361 and
engaging the ring 302. Casing parts 340 project beyond the outer limit of the ring
302 and a dust cover 364 is provided therebetween. A slot (not shown) is provided
in the cover 364 to allow movement of the actuating arm (also not shown).
[0026] The pinion support ring is absent in this embodiment, the pinion wheel 330 and idler
wheels (not shown) being rotatably mounted on the casing parts 340 by means of bolts
365.
[0027] In use, the valve is opened or closed by rotating the outer ring 302 relative to
the casing parts 340. The engagement of inward facing teeth on the outer ring 302
and teeth on the pinion wheel 330 causes the pinion wheel 330 to rotate. The engagement
of teeth on the pinion wheels with outward facing teeth on the second ring 316 causes
rotation of the second ring 316 when the outer ring 302 is rotated. Again, increased,
angular displacement of the second ring 316 is achieved by the epicyclic gearing and
the stepped pinion wheel described previously.
1. A valve comprising a flexible sleeve having first and second axially spaced sleeve
portions; first and second coaxially disposed, relatively angularly movable rings
relative to which the first and second sleeve portions are respectively fixed; and
means for mounting the first and second rings around an opening through which the
flow of material is to be controlled by the valve; wherein the first and second rings
form parts of an epicyclic gear mechanism; and wherein means are provided for effecting
angular movement of part of the epicyclic gear mechanism between a first position
corresponding to a fully closed position of the valve and a second position corresponding
to a fully open position of the valve, said epicyclic gear mechanism producing an
increased angular relative movement of the rings for a given angular movement produced
by said angular movement effecting means.
2. A valve as claimed in claim 1, wherein the first ring is fixed against angular
movement, the epicyclic gear mechanism comprises a carrier upon which pinion wheels
are rotatably mounted, said pinion wheels drivingly engage the first and second rings
and said angular movement effecting means can be used to move the carrier such that
angular movement of the carrier is transmitted, by cooperation of said pinion wheels
with said first and second rings, to the second ring and produces a correspondingly
increased angular movement thereof.
3. A valve as claimed in claim 1, wherein the epicyclic gear mechansim comprises a
plurality of pinion wheels rotatably mounted on said mounting means and engaging said
first and second rings, said angular movement effecting means being used to move one
of said rings such that angular movement of said one of said rings is tramsmitted
by cooperation of said pinion wheels with said first and second rings to the other
of said rings and produces a correspondingly increased angular movement thereof.
4. A valve as claimed in any preceding claim, wherein at least one of said pinion
wheels is toothed, the teeth engaging with corresponding teeth on the inner surface
of the first ring and the outer surface of the second ring.
5. A valve as claimed in any preceding claim, wherein a portion of each pinion wheel
which engages the first ring has a different diameter to a portion of.each wheel which
engages the second ring so that the angular movement of the rings produced by the
angular movement effecting means is further increased.
6. A valve as claimed in claim 2, wherein the first ring comprises a casing and a
fixed ring, the fixed ring being fixedly connected to the casing and engaging said
pinion wheels, said first flexible sleeve portion being fixed relative to the casing.
7. A valve as claimed in claim 2 or 6 wherein, the means for rotating the carrier
is an arm attached at one end to said carrier and at its other end to mechanical means,
for providing movement of said arm.