A. Field of the Invention
The present invention relates to fittings for use with flexible hoses used to transport liquid food products under pressure. More particularly the invention relates to sanitary hose couplers attachable to hoses and releasably joinable together in a fluid pressure-tight connection.
B. Description of Background Art
In the manufacture and packaging of liquid food products and pharmaceuticals, flexible hoses are used extensively for transporting liquid products under pressure between various processing and container-filling stations. Such liquid products have different viscosities, ranging from typically low viscosities for beverages, to relatively high viscosities for products such as jellies. Accordingly, hoses and hose fittings used for such applications must withstand the relatively high pressures required for transporting liquid materials at reasonably high flow rates.
Hose and hose fittings used in the food and drug industries for transporting liquid food and drug products, especially those intended for human consumption, must meet certain performance requirements in addition to maintaining a leak-tight connection under pressure, as alluded to above. For example, U.S. Food and Drug Administration (FDA) regulations require that machines used to fill containers with liquid food or drug products must be sterilizable, and readily cleaned of liquid products which might be trapped in cavities within machine components, and thereby providing a growth media for microbes. Accordingly, a goal in the design and construction of machines used for the processing or handling liquid food and drug products, such as production line container filling machines, is that such machines be Cleanable-In-Place (C.I.P.), with no or minimal disassembly of machine components required during the cleaning process. Since hoses used to transport liquid food or drug products between various production processing machines must also be periodically cleaned, the ends of such hoses are generally fitted with a connecting element or coupler which is releasably joinable to a compatible coupler attached to a machine component or to another hose.
A variety of hoses fitted with couplers on one or both ends are available. Some types of existing couplers are permanently attached to hoses, usually at a factory which manufactures the coupler. Other types of currently available coupler fittings are reusable, and some are attachable to hoses in the field. Field attachability of hose fittings is desirable since it enables such fittings to be attached to the ends of hoses which are cut to a particular length at a location where the fitting is to be used, such as a liquid food or drug processing production line.
Many existing hose fittings and couplers for use with flexible hoses include a tubular component or ferrule member which has a plurality of longitudinally spaced apart circumferentially disposed, radially outwardly projecting gripping members such as annular rings or ridges, barbs or ribs which are provided to grip the inner circumferential wall surface of the hose and secure the fitting to the hose, when the tubular component is press fitted into the hose bore. However, that type of fitting is problematic for use in the food and drug industries, for the following reason.
Initially, gripping members on the exterior surface of a tubular fitting element press-fitted into the bore of a flexible hose usually form an adequate fluid-pressure-tight seal with the inner cylindrical surface of the hose bore wall. Moreover, since most such tubular elements have a plurality of longitudinally spaced apart gripping members, leakage of fluid under pressure, or blow-by, around a single gripping element will not necessarily cause a breach of the fluid-tight pressure seal which would allow leakage of fluid product to the outside of the hose, since the other gripping members spaced longitudinally inwards of an outer gripping element provide redundant, back-up fluid pressure-tight seals. However, it has been found that, cyclically pressurizing and de-pressurizing such existing hose fittings with liquid product can cause the following problem.
When a hose is pressurized, expansion of the hose outwards from the gripping elements of a hose fitting may allow liquid product to flow longitudinally inwardly beyond one or more seals made by the gripping elements. Then, when the hose is de-pressurized, the hose contracts, trapping liquid food product that has leaked by the sealing elements, in the valleys, grooves or other such cavities which separate the sealing elements. Thus, presently existing hose fittings including couplers which utilize external gripping members on the outer surface of a tubular press-fit fitting component generally have cavities in which liquid products may be trapped, and are therefore, not truly cleanable-in-place. The unavailability of a sanitary hose coupler meeting all of the above mentioned criteria of being cleanable-in-place, readily attachable to the end of a hose in the field, and readily connected and disconnected to a compatible coupler attached to another hose or to a machine component, was a motivation for the present invention.
An object of the present invention is to provide a sanitary hose coupler for liquid products which is fastenable to a flexible hose to form therewith a fluid pressure-tight flow path devoid of cavities which might trap a portion of liquid product flowing through the hose.
Another object of the invention is to provide a sanitary tubular hose coupler which has a first, outer longitudinal end portion sealably and releasably coupleable to the outer end portion of another coupler.
Another object of the invention is to provide a re-attachable sanitary hose coupler which has a first, outer longitudinal end portion sealably and releasably coupleable to the outer end portion of another coupler, and a second, inner longitudinal end portion which is removably attachable in a fluid pressure-tight connection to an end of a flexible hose.
Another object of the invention is to provide a sanitary hose coupler which has a first, outer longitudinal end portion sealably and releasably coupleable to the outer end portion of another coupler, and a second, inner longitudinal end portion which is permanently attachable in a fluid pressure-tight connection to an end of a flexible hose.
Various other objects and advantages of the present invention, and its most novel features, will become apparent to those skilled in the art by perusing the accompanying specification, drawings and claims.
It is to be understood that although the invention disclosed herein is fully capable of achieving the objects and providing the advantages described, the characteristics of the invention described herein are merely illustrative of the preferred embodiments. Accordingly, I do not intend that the scope of my exclusive rights and privileges in the invention be limited to details of the embodiments described. I do intend that equivalents, adaptations and modifications of the invention reasonably inferable from the description contained herein be included within the scope of the invention as defined by the appended claims.
Briefly stated, the present invention comprehends sanitary hose couplers for attachment to flexible hoses used to transport liquid products under pressure. Hose couplers according to the present invention have a first, inner longitudinal end portion which includes an attachment structure adapted to make a fluid pressure-tight seal with the end of a flexible hose, and a second, outer longitudinal end portion which includes a connector flange adapted to be releasably coupled to another coupler which has a mating flange, the other coupler being either another coupler according to the present invention, or a coupler of an existing type which has a suitable connection flange.
A first, re-attachable or removably attachable embodiment of a sanitary hose coupler according to the present invention includes a longitudinally elongated circular cross section connector body having disposed through its length a coaxial bore. The connector body has a relatively short cylindrically-shaped tubular portion which is terminated at a front or outer longitudinal end thereof by an annular ring-shaped front connector flange that has a front or outer transverse face in which is formed a concentric annular ring-shaped groove. The connector flange has a short cylindrical body which is joined at a rear or inner end thereof to the tubular portion of the body by a frusto-conically-shaped shoulder. The connector body includes an elongated externally threaded cylindrical section located longitudinally inwards of the short tubular section. The threaded cylindrical section has a rear or longitudinally inwardly located, annular ring-shaped transverse end with which forms a shoulder. A radially inwardly tapered, elongated frusto-conic nose section protrudes rearwardly from the shoulder. The nose section has a smooth outer wall surface and is of the proper size to be insertably receivable into the bore of a flexible hose or tube sufficiently far for the transverse outer annular end wall of the hose to butt up against the rear surface of the shoulder of the threaded portion of the connector body. Inserting the frusto-conically tapered nose of the connector body into the bore of a resiliently deformable hose distorts the inner and outer wall surfaces of the hose into generally frusto-conic shapes.
A re-attachable sanitary hose coupler according to the present invention also includes a compression ring which has a cylindrical outer surface, an annular ring-shaped inner transverse end wall, and a frusto-conic inner wall surface which tapers radially outwardly in a forward longitudinal direction to a front or outer transverse end wall of larger inner diameter than the inner transverse end wall. The tapered inner wall surface of the compression ring is segmented into a longitudinally disposed sequence of radially inwardly protruding, annular ring-shaped ridges. The ridges are of stepped diameter and approximately equal length. Each of the ridges has a frusto-conically-shaped longitudinal cross section, which tapers radially outwardly from the rear or inner transverse end wall of the compression ring, to a front or outer transverse end wall of larger inner diameter than the rear transverse end wall.
Each adjacent pair of frusto-conically contoured, annular ring-shaped ridges in the inner cylindrical wall surface of the compression ring has located therebetween a radially outwardly protruding groove which has a generally triangularly-shaped longitudinal cross section, the groove having a stepped shoulder which intersects an adjacent ridge.
A re-attachable sanitary hose coupler according to the present invention includes as a third component, an elongated cylindrically-shaped compression nut or bushing. The compression nut has at a rear or inner longitudinal end thereof a transversely disposed flat, annular ring-shaped flange wall. The rear end transverse flange wall has through its thickness dimension a central coaxial hose bore of the proper diameter to provide clearance for the largest outer diameter hose which the coupler is intended to be used with. The hose bore in the rear flange wall communicates with a rear hollow cylindrical space within the interior of the compression nut, which has a smooth inner wall that has an inner diameter greater than the outer diameter of the compression ring, and a length greater than that of the compression ring. Located longitudinally forward of the rear, smooth-bore portion of the compression nut is a front, internally threaded cylindrical portion. The latter has formed in the inner cylindrical wall surface thereof internal helical threads which are disposed longitudinally forward from the rear smooth-bore portion of the compression nut to the front or outer longitudinal end thereof, and are of the proper size and pitch to threadably receive the external threads on the connector body.
The re-attachable sanitary hose coupler according to the present invention is attached to the free end of a flexible hose as follows. First, the end of the hose is inserted forwardly into the hose bore of the compression nut, and forwardly into the hose bore of the compression ring. The nose piece of the connector body is then forcibly inserted longitudinally rearwards into the hose bore, deforming both inner and outer walls of an end portion of the hose from generally cylindrical shapes to generally frusto-conic shapes. The compression nut is then slid forward over the compression ring and hose sufficiently far for the external threads of the connector body to contact the internal threads of the compression nut. Relative torque is then applied between the compression nut and connector body, to thread the connector body rearwardly into the compression nut. The ensuing longitudinal contraction of the space between the rear shoulder of the threaded portion of the coupler body, and the front surface of the rear compression nut flange wall, causes the compression nut flange wall to press in a longitudinally forward direction on the rear end wall of the compression ring. This force in turn causes the ridged, frusto-conically-shaped inner wall of the compression ring to press tightly into the expanded outer wall surface of the hose end, thus causing the shoulders of the ridges to dig into the outer wall surface of the hose, and the outer wall surface of the hose to deform by cold flow into the grooves between the ridges. Thus installed, the re-attachable sanitary coupler according to the present invention forms a fluid pressure-tight seal with the hose, devoid of any cavities in the flow path through the coupler which might trap flowing liquid product.
A second, permanently attached embodiment of a sanitary hose coupler according to the present invention is of simpler construction than the re-attachable embodiment described above, and has only two component parts, which consist of a connector body of simplified construction, and an external compression sleeve which combines functions of the compression ring and compression nut of the re-attachable embodiment of the hose coupler described above.
The connector body of a permanently attachable hose coupler according to the present invention has a relatively short cylindrically-shaped tubular portion which is terminated at a front or outer longitudinal end thereof by an annular ring-shaped, front or outer connector flange that has a front or outer transverse face in which is formed a concentric annular ring-shaped groove. The front connector flange has a short cylindrical body which is joined at a rear or inner longitudinal end thereof to the tubular portion of the connector body by a frusto-conically-shaped shoulder. The front tubular portion of the connector body is terminated at a rear or inner longitudinal end thereof by a radially outwardly protruding, annular ring-shaped rear locking flange, which has a rear transversely disposed shoulder. A radially inwardly tapered, elongated frusto-conic nose section protrudes rearwardly from the shoulder. The nose section has a smooth outer wall surface of the proper size to be insertably receivable into the bore of a flexible hose or tube sufficiently far for the front or outer transverse annular end wall of the hose to butt up against the shoulder of the rear locking flange. Inserting the nose of the connector body into the bore of a resiliently deformable hose distorts the inner and outer wall surfaces of the hose into generally frusto-conic shapes.
A permanently attachable sanitary hose coupler according to the present invention also includes a compression sleeve which has a cylindrical outer surface, an annular ring-shaped rear transverse end wall at the rear or inner longitudinal end of the sleeve, and a generally frusto-conically-shaped inner circumferential wall surface which tapers radially outwardly in a forward longitudinal direction to a front or outer transverse end wall of larger inner diameter than the rear or inner transverse end wall. The tapered inner wall surface of the compression sleeve is segmented into a longitudinally disposed sequence of radially inwardly protruding, annular ring-shaped ridges. The ridges are of stepped diameter and approximately equal length. Each of the ridges has a frusto-conically-shaped longitudinal cross section, which tapers radially outwardly from the rear or inner transverse end wall of the compression ring, to a front or outer transverse end wall of larger inner diameter than the rear transverse end wall.
Each adjacent pair of frusto-conically contoured, annular ring-shaped ridges in the inner cylindrical wall surface of the compression sleeve has located therebetween a radially outwardly protruding groove which has a generally triangularly-shaped longitudinal cross section, the groove having a stepped shoulder which intersects an adjacent ridge.
The permanently attachable sanitary hose coupler according to the present invention is attached to the free end of a flexible hose as follows. First, the end of a flexible hose is inserted into the rear hose bore of the compression sleeve. The nose piece of the connector body is then forcibly inserted longitudinally rearwardly into the hose bore, deforming both the inner and outer walls of an end portion of the hose located rearwards or inwards of the outer transverse end face of the hose, from generally cylindrical to generally frusto-conic shapes. The compression sleeve is then advanced forward forcibly against the deformed outer wall surface of the end portion of the hose, by using a press or similar tool, sufficiently far for the front annular edge wall of the compression sleeve to move longitudinally forward or outwards of the front annular transverse surface of the rear locking flange of the connector body. This forcing action causes the ridged, frusto-conically-shaped inner wall surface of the compression sleeve to press tightly into the radially expanded and frusto-conically deformed outer wall surface of the hose end, thus causing the shoulders of the ridges protruding radially inwards from the inner wall surface of the sleeve to dig into the outer wall surface of the hose, and the outer wall surface of the hose to deform by cold flow into the grooves between the ridges.
A final step in installing the permanently attachable sanitary hose coupler to the hose consists of permanently deforming an outer end portion of the cylindrical wall of the compression sleeve radially inwardly to form an angled annular locking lip flange which presses against the front surface of the rear connector body locking flange, thereby permanently securing the compression sleeve into locking engagement with the connector body. Deformation of the front end wall of the compression sleeve to form the annular locking lip flange is accomplished by impacting the front end wall with a punch which has in a front surface thereof a notch shaped complementarily to the desired outer contour of the lip flange, the rear surface of the punch being impacted by a hammer as the hammer and punch are orbited circumferentially around the sleeve end wall. Alternatively, the compression sleeve end wall can be deformed by a ring-shaped die, which may optionally be incorporated into the press used to press the compression sleeve and connector body together.
With the connector body and compression sleeve of the permanently attachable sanitary hose coupler attached to a hose as described above, the hose and coupler are joined together in a permanent fluid pressure-tight seal, devoid of any cavities in the path of liquid flowing product flowing through the hose and coupler, which cavities might trap flowing liquid products.
Referring first to
As shown in
Intermediate cylindrical portion 28 of connector body 25 has formed in an outer cylindrical wall surface thereof a helically disposed thread 30. Also, intermediate threaded portion 28 of connector body 25 has an annular ring-shaped, transversely disposed front end face 31 which joins the threaded intermediate portion to a short front, cylindrically-shaped tubular portion 32. The latter has a smooth outer cylindrical wall surface of a uniform outer diameter approximately the same as the outer diameter of the front end of rear frusto-conically-shaped nose piece 26. Front tubular portion 32 of connector body 25 is terminated at a front or longitudinally outwardly located or front end thereof by an annular ring-shaped front connector flange 33. The latter has a frusto-conically-shaped rear transverse end wall 34, and a flat front transverse end wall 35, in which is formed a concentric annular ring-shaped groove 36. Groove 36 is provided for receiving an O-ring C, adapting flange 33 to make a compressive fluid pressure-tight seal with the flange D of another hose coupler E, when the two flanges are pressed towards one another, as by a toggle clamp F. Coupler E may be of a conventional prior art design, or a coupler according to the present invention.
Referring now to
Referring still to
The uncut portion of tapered inner wall surface 39 between each intersection of an oblique side 47 of groove 45 with the inner wall surface, and the rear transverse edge wall 46 of an adjacent, longitudinally outwardly spaced apart groove, forms a ridge 49. Although the exact number of grooves 45 formed in inner tapered wall surface 39 of compression ring 23 is not critical, preferably as shown in
Referring now to
A preferred method of removably attaching removably attachable sanitary hose coupler 20 to a hose may be best understood by referring to
A first step in attaching sanitary hose coupler 20 to a hose A includes inserting an end of hose A 25 forwardly through bore 22 of compression nut 21, and then through bore 24 of compression ring 23, as shown in
Referring now primarily to
Referring now to
As shown in
Referring now to
Referring still to
The uncut portion of tapered inner wall surface 89 between each intersection of an oblique side 97 of groove 95 with the inner wall surface, and the rear transverse edge wall 96 of an adjacent, longitudinally outwardly spaced apart groove, forms a ridge 99. Although the exact number of grooves 95 formed in inner tapered wall surface 89 of compression ring 73 is not critical, preferably as shown in
A preferred method of permanently attaching permanently attachable sanitary hose coupler 70 to a hose may be best understood by referring to
As shown in
A final step in installing permanently attachable sanitary hose coupler 70 to a hose consists of permanently deforming an outer end portion 105 of the cylindrical wall 104 of compression sleeve 71 which protrudes forward or longitudinally outwards of front transverse end wall of rear connector body locking flange 78, thus forming an angled locking lip flange 106 which presses against the front surface of the rear connector body locking flange, thereby permanently securing the compression sleeve into locking engagement with the connector body. Deformation of compression sleeve end wall 105 to form an annular locking lip flange 106 may be accomplished in the manner illustrated in
Referring now primarily to