Abstract:
A sanitary hose coupler attachable in a fluid pressure-tight, void-free connection to a resiliently deformable hose for conveying liquid food or drug products under pressure, which is releasably coupleable in a fluid pressure-tight connection to a compatible coupler, comprises an elongated tubular connector body having a rearwardly protruding frusto-conically tapered nose piece forcibly insertable into the bore of a hose, a hollow cylindrical compression member which has through its length a central frusto-conically shaped bore and a clamping member for exerting a compression force couple on the compression member and connector body, thereby pressing the tapered inner wall surface of the compression member into a fluid pressure-tight seal with the outer surface of an end portion of the hose which is expanded by insertion of the nose piece into the hose bore.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     A. Field of the Invention  
         [0002]     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.  
         [0003]     B. Description of Background Art  
         [0004]     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.  
         [0005]     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.  
         [0006]     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.  
         [0007]     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.  
         [0008]     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.  
         [0009]     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.  
       OBJECTS OF THE INVENTION  
       [0010]     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.  
         [0011]     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.  
         [0012]     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.  
         [0013]     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.  
         [0014]     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.  
         [0015]     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.  
       SUMMARY OF THE INVENTION  
       [0016]     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.  
         [0017]     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.  
         [0018]     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.  
         [0019]     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.  
         [0020]     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.  
         [0021]     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.  
         [0022]     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.  
         [0023]     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.  
         [0024]     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.  
         [0025]     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.  
         [0026]     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.  
         [0027]     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.  
         [0028]     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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0029]      FIG. 1  is an exploded perspective view of a removably attachable embodiment of a sanitary hose coupler according to the present invention, showing the coupler oriented for attachment to a first hose segment, and adjacent to a mating coupler already attached to a second hose segment.  
         [0030]      FIG. 2A  is a longitudinal sectional view of the coupler of  FIG. 1 , taken in the direction of line  2 A- 2 A.  
         [0031]      FIG. 2B  is a fragmentary view of the coupler of  FIG. 2A  on an enlarged scale, taken in the direction of line  2 B- 2 B.  
         [0032]      FIGS. 3A-3D  are left side elevation views of the hose and three components of the coupler of  FIG. 1 , taken in the directions  3 A- 3 A,  3 B- 3 B,  3 C- 3 C, and  3 D- 3 D, respectively.  
         [0033]      FIGS. 4A-4D  are right side elevation views of the hose and three components of the coupler of  FIG. 1 , taken in the directions  4 A- 4 A,  4 B- 4 B,  4 C- 4 C, and  4 D- 4 D, respectively.  
         [0034]      FIGS. 5A-5D  are perspective views showing a method of attaching the coupler of  FIGS. 1 and 2  to a hose segment, in which  FIG. 5A  shows a compression nut and compression ring slipped over the end of a hose,  FIG. 5B  shows a connector body inserted into the hose bore,  FIG. 5C  shows a clamp installed on the connector body to facilitate applying a counter torque to the connector body, and  FIG. 5D  shows a wrench being used to exert a tightening torque on the compression nut.  
         [0035]      FIG. 6  is a longitudinal sectional view of the coupler of  FIG. 5 , showing the coupler of  FIGS. 1 and 2  removably attached to a hose segment.  
         [0036]      FIG. 7  is an exploded perspective view of a permanently attachable embodiment of a sanitary hose coupler according to the present invention.  
         [0037]      FIG. 8  is a longitudinal sectional view of the coupler of  FIG. 7 , taken in the direction of line  8 - 8 .  
         [0038]      FIGS. 9A-9C  are left side elevation views of the hose and two components of the coupler of  FIG. 7 , taken in the directions  9 A- 9 A,  9 B- 9 B, and  9 C- 9 C, respectively.  
         [0039]      FIGS. 10A-10C  are right side elevation views of the hose and two components of the coupler of  FIG. 7 , taken in the directions  10 A- 10 A,  10 B- 10 B, and  10 C- 10 C,  10 C, respectively.  
         [0040]      FIGS. 11A-11D  are perspective views showing a method of attaching the coupler of  FIGS. 7 and 8  to a hose segment, in which  FIG. 11A  shows a compression sleeve slipped over the end of a hose,  FIG. 11B  shows a connector body inserted into the hose bore,  FIG. 11C  shows the compression sleeve pressed forward to overlie a rear flange of the connector body, and  FIG. 11D  shows a front transverse end wall of the compression sleeve deformed radially inwardly over the rear flange of the connector body to permanently secure the coupler to the hose.  
         [0041]      FIG. 12  is a longitudinal sectional view of the coupler of  FIG. 11 , showing the coupler permanently attached to a hose segment.  
         [0042]      FIG. 13  is a view of a press which is useable to attach the coupler of  FIGS. 7-12  to a hose.  
         [0043]      FIG. 14  is a fragmentary vertical longitudinal sectional view of the press of  FIG. 13 , taken in the direction of line  14 A- 14 A.  
         [0044]      FIG. 14B  is a fragmentary horizontal transverse sectional view of the press of  FIG. 13  taken in the direction of line  14 B- 14 B.  
         [0045]      FIG. 15  is a longitudinal vertical sectional view of the press of  FIG. 13 , taken in the direction of line  15 - 15  and showing the manner at forming a locking lip flange on the coupler. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0046]      FIGS. 1-6  illustrate various aspects of a removably attachable sanitary hose coupler according to the present invention, and  FIGS. 7-12  illustrate a permanently attachable embodiment of the invention.  
         [0047]     Referring first to  FIGS. 1-4 , a removably attachable sanitary hose coupler  20  according to the present invention may be seen to include a coaxially alignable set of three circularly symmetric component parts, including a rear compression nut  21  which as through its length a longitudinally disposed circular bore  22  which is adapted to insertably and loosely receive a hose A, a longitudinally intermediately located compression ring  23  which has through its length a longitudinally disposed circular bore  24  which is adapted to insertably and snugly receive a hose A, the outer diameter of the compression ring being smaller than bore  22  of the compression nut, and a front or longitudinally outwardly located connector body  25  which has a rear radially inwardly tapered frusto-conic nose piece  26  which is adapted to be forcibly inserted into the bore B of hose A.  
         [0048]     As shown in  FIGS. 1, 2 ,  3 D and  4 D connector body  25  has a hollow tubular shape and has disposed longitudinally through its length a cylindrical circular bore  27  of uniform diameter. Connector body  25  includes an elongated, externally threaded, intermediate cylindrical portion  28 , the intermediate portion having an annular ring-shaped, transversely disposed rear end face  29  which forms a shoulder that joins the front longitudinal end of the nose piece.  
         [0049]     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.  
         [0050]     Referring now to  FIGS. 3C and 4C  in addition to  FIGS. 1 and 2 , it may be seen that compression ring  23  of removably attachable hose coupler  20  according to the present invention has a cylindrical outer surface  37 , a rear or inner longitudinally located transverse end wall  38 , and a frusto-conically tapered inner wall surface  39  which tapers radially outwardly to a front or outer longitudinal transverse end wall  40  which has a larger inner diameter than the rear transverse end wall. As shown in  FIG. 2 , the cone angle G of tapered inner wall surface  39  is preferably larger than that of cone angle H of connector body nose piece  26 , for a reason which will be described below. In an example embodiment of coupler  20 , tapered inner wall surface  39  of compression ring  23  had a cone angle G of about 7 degrees±2 degrees, and connector body nose piece  26  had a cone angle H of about 6 degrees±2 degrees, for a hose made of reinforced silicone or Teflon® and having an inner diameter of ⅝ inches and a wall thickness of about 0.170 inch. It is believed that the cone angles G and H should be increased about one degree for each inch increase in the inner diameter of hose A. However, hoses made of harder, less flexible materials such as Teflon® require somewhat smaller cone angles. In any event, the exact value of cone angles is not extremely critical, and the adjustment of the cone angles to suite hose materials of a given pliability may be readily made by those skilled in the art, in view of the present disclosure.  
         [0051]     Referring still to  FIG. 2 , it may be seen that the frusto-conic shape of tapered inner wall surface  39  of compression ring  23  is preferably modified by cylindrical front and rear entrance counter bores  41  and  42 , respectively, which form relatively short, cylindrically shaped, untapered portions  43  and  44 , respectively, in tapered inner wall surface  39 . As shown in  FIG. 2 , tapered inner wall surface  39  of compression ring  23  has formed therein a longitudinally spaced apart sequence of radially inwardly protruding, annular ring-shaped, triangular cross section grooves  45 . Each groove  45  has a generally transversely disposed rear edge  46 , and a longer oblique edge  47  which angles radially outwardly and forward from the rear edge to an uncut portion of inner wall surface  39 . Thus, each groove  45  has at a rear or inner longitudinal end thereof a shoulder  48  formed by the intersection of transversely disposed rear edge  46  of the groove with tapered inner wall surface  39 . Shoulder  48  has a relatively sharp vertex angle, being about 90 degrees plus one-half the cone angle G. On the other hand, oblique edge  47  of each groove  45  intersects tapered inner wall surface  39  at a relatively large obtuse angle.  
         [0052]     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  FIG. 2 , the compression ring has at least two longitudinally spaced apart grooves  45  which form therebetween a ridge  49 . It should be noted that tapered, uncut portion  50  in inner wall surface  39  rearward of the rear groove  45 R, and tapered, uncut portion  51  of inner wall surface  39  forward of front groove  45 F has a shapes similar to that of ridges  49 , and serves a similar function, as will be described in detail below.  
         [0053]     Referring now to  FIGS. 3B and 4B  in addition to  FIGS. 1 and 2 , it may be seen that compression nut  21  of removably attachable hose coupler  20  has the shape of a longitudinally elongated bushing which includes a cylindrical body  52  that has an outer cylindrical wall surface  53  of uniform circular transverse cross section. Body  52  of compression nut  21  is terminated at a rear or inner longitudinal end thereof by a transversely disposed, flat, annular ring-shaped flange wall  54 . Flange wall  54  has through its thickness dimension a central coaxial hose bore  55  of the proper diameter to provide clearance for the largest outer diameter hose which coupler  20  is intended to be used with. Hose bore  55  communicates with a hollow cylindrically-shaped space  56  within compression nut body  52 . The inner cylindrical wall surface  57  of compression nut body  52  has a rear longitudinal portion  58  which has a smooth bore of larger diameter than the outer diameter of compression ring  28 , and a length greater than that of the compression ring. Inner cylindrical wall surface  57  of compression nut body  52  also has a front longitudinal portion  59  in which is formed a helical thread  60  that is disposed forward from rear smooth bore portion  58  to a front transverse end wall  61  of body  52 . Internally threaded portion  59  of compression nut body  52  is of the proper size and pitch to insertably and threadably receive externally threaded portion  28  of connector body  25 . As shown in  FIG. 2 , rear flange wall  54  of compression nut  21  has an annular ring-shaped front wall surface  62 . Also, as may be seen best by referring to  FIGS. 2 and 3 B, rear transverse end wall  54  has formed therein a pair of diametrically opposed, transversely disposed notches  63  which have parallel, longitudinally disposed, radially inwardly recessed flat edges or flats  64 .  
         [0054]     A preferred method of removably attaching removably attachable sanitary hose coupler  20  to a hose may be best understood by referring to  FIGS. 5A-5D  and  6  in addition to  FIG. 1 .  
         [0055]     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  FIG. 5A . Next, as shown in  FIG. 5B , nose piece  26  of connector body is forcibly inserted into bore B of hose A. As shown in  FIG. 5D , compression nut  21  is then slid forward on hose A and over compression ring  23  sufficiently far forward for externally threaded portion  28  of connector body  25  to be received within the front, internally threaded portion of compression nut  21 . A torque is then applied on compression nut  21  relative to connector body  25 , to draw those elements axially together. This torque may be conveniently applied by a wrench slipped over notches  63  to engage flats  64 . During the process of threadably tightening together compression nut  21  and connector body  25 , a convenient way of applying a counter-torque to the connector body is by gripping the connector body with a toggle clamp F of the type shown in  FIG. 1 . Thus, as may be understood by referring to  FIGS. 1, 5C  and  5 D, flange  33  of connector body  25  and a flange D of another coupler E are positioned face to face within a slot S of a toggle clamp F, and the toggle clamp closed and tightened as shown in  FIG. 5C . Toggle clamp F may then be gripped by one of a person&#39;s hands while the other hand is used to apply torque through wrench W to compression nut  21 , as shown in  FIG. 5D .  
         [0056]     Referring now primarily to  FIG. 6 , it may be understood that threadably tightening connector body  25  into compression nut  21  longitudinally contracts the spacing between inner, rear shoulder wall  29  of the connector body, and front annular surface  62  of rear flange wall  54  of the compression nut. This contraction causes front annular surface  62  of rear compression nut flange wall  54  to press in a longitudinally forward direction against rear transverse end wall  38  of compression ring  23 . The longitudinally forward directed force on rear end wall  38  of compression ring  23  in turn causes frusto-conically tapered inner wall surface  39  of the compression ring to press tightly against the frusto-conically deformed outer wall surface of hose A, forcing shoulders  48  adjacent to ridges  49  in the inner wall surface of the compression ring to “dig in” to the outer wall surface of the hose, and those portions of the hose located between the ridges to cold flow into grooves  45  between the ridges. Thus installed, removably attachable sanitary hose coupler  20  according to the present invention forms a fluid pressure-tight seal with hose A. Importantly, as shown in  FIG. 6 , the fluid pressure-tight seal between coupler  20  and hose A is devoid of any cavities in a liquid product flow path through bore B of the hose and bore  27  of the coupler; the absence of any such cavities guarantees that there are no places in the coupler which might serve as traps for liquid product.  
         [0057]     Referring now to  FIGS. 7-12 , a permanently attachable sanitary hose coupler  70  according to the present invention may be seen to include a coaxially alignable set of two circularly symmetric component parts, including a rear or longitudinally inwardly located compression sleeve  71  which has through it length a longitudinally disposed circular cross section coaxial bore  22  which is adapted to insertably receive a hose A, and a front or longitudinally outwardly located connector body  75  which has a rear frusto-conically-shaped nose piece  76  which is adapted to be forcibly inserted into bore B of hose A.  
         [0058]     As shown in  FIGS. 7, 8 ,  9 C and  10 C, connector body  75  has a hollow tubular shape and has disposed longitudinally through its length a cylindrical circular bore  77  of uniform diameter. Connector body  75  also has a relatively short cylindrically-shaped front tubular portion  82  which is terminated at a front or outer longitudinal end thereof by an annular ring-shaped front or outer connector flange  83  that has a frusto-conically shaped rear transverse end wall  84  and a flat front transverse end wall  85  in which is formed a concentric annular ring-shaped groove  86 . Front tubular portion  82  of connector body  75  is terminated at a rear or inner longitudinal end thereof by a radially outwardly protruding, annular ring-shaped rear locking flange  78 , which has a rear transversely disposed shoulder  79 . Locking flange  78  also has a frusto-conically tapered front annular ring-shaped transversely disposed front end face  81  which joins the rear locking flange to front tubular portion  82  of connector body  75 . Tubular front portion  82  of connector body  75  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  76 . Nose piece  76  protrudes rearwardly from rear transversely disposed shoulder  79  of rear locking flange  78 . Also, nose piece  76  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 end wall of the hose to butt up against rear shoulder  79  of rear locking flange  78 .  
         [0059]     Referring now to  FIGS. 9B and 10B  in addition to  FIGS. 7 and 8 , it may be seen that compression sleeve  71  of removably attachable sanitary hose coupler  70  according to the present invention has a cylindrical outer surface  87 , a rear or inner longitudinally located transverse end wall  88 , and a frusto-conically tapered inner wall surface  89  which tapers radially outwardly to a front or outer longitudinal transverse end wall  90  which has a larger inner diameter than the rear transverse end wall. As shown in  FIG. 8 , the cone angle J of tapered inner wall surface  89  is preferably larger than that of cone angle K of connector body nose piece  76 , for a reason which will be described below. In an example embodiment of coupler  70 , tapered inner wall surface  89  of compression sleeve  71  had a cone angle J of about 7 degrees±2 degrees, and connector body nose piece  76  had a cone angle K of about 6 degrees±2 degrees, for a hose made of reinforced silicone or Teflon® and having an inner diameter of ⅝ inches and a wall thickness of about 0.170 inch. It is believed that the cone angles G and H should be increased about one degree for each inch increase in the inner diameter of hose A. However, hoses made of harder, less flexible materials such as Teflon® require somewhat smaller cone angles. In any event, the exact value of cone angles is not extremely critical, and the adjustment of the cone angles to suite hose materials of a given pliability may be readily made by those skilled in the art, in view of the present disclosure.  
         [0060]     Referring still to  FIG. 8 , it may be seen that tapered inner wall surface  89  of compression sleeve  71  is preferably modified by cylindrical front and rear entrance counterbores  91  and  92 , respectively, which form relatively short, cylindrically shaped, untapered portions  93  and  94 , respectively, in tapered inner wall surface  39 . As shown in  FIG. 2 , tapered inner wall surface  89  of compression ring  73  has formed therein a longitudinally spaced apart sequence of radially inwardly protruding, annular ring-shaped, triangular cross section grooves  95 . Each groove  95  has a generally transversely disposed rear edge  96 , and a longer oblique edge  97  which angles radially outwardly and forward from the rear edge to an uncut portion of inner wall surface  89 . Thus, each groove  95  has at a rear or inner longitudinal end thereof a shoulder  98  formed by the intersection of transversely disposed rear edge  96  of the groove with tapered inner wall surface  89 . Shoulder  98  has a relatively sharp vertex angle, being about 90 degrees plus one-half the cone angle J. On the other hand, oblique edge  97  of each groove  95  intersects tapered inner wall surface  89  at a relatively large obtuse angle.  
         [0061]     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  FIG. 8 , the compression ring has at least two longitudinally spaced apart grooves  95  which form therebetween a ridge  99 . It should be noted that tapered, uncut portion  101  of inner wall surface  89  forward of front groove  95 F has a shape similar to those of ridges  99 , and serves a similar function, as will be described in detail below.  
         [0062]     A preferred method of permanently attaching permanently attachable sanitary hose coupler  70  to a hose may be best understood by referring to  FIGS. 7, 8 ,  11 A- 11 D,  12 , and  13 - 15 .  
         [0063]     As shown in  FIG. 11A , a first step in attaching sanitary hose coupler  70  to a hose A includes inserting an end of hose A forwardly through bore  72  of compression sleeve  71 . Next, as shown in  FIG. 11B , nose piece  76  of connector body  75  is forcibly inserted into bore B of hose A. Connector body  75  and compression sleeve  71  are then squeezed together by exerting a longitudinally inwardly directed compressive force couple on front transverse surface  85  of connector body flange  83 , and rear transverse end wall  88  of compression sleeve  71 , respectively. This force may be conveniently applied by a press, such as press  110  of  FIGS. 13, 14A ,  14 B, and  15 .  
         [0064]     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  FIG. 15 . As shown in  FIG. 15 , deformation of end wall  105  of compression sleeve  71  is accomplished by impacting the end wall with a punch  120  which has in a front surface  121  thereof a notch  122  shaped complementarily to the desired outer contour of locking lip flange  106 . The rear surface  123  of punch  120  is impacted by a hammer  124  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 optionally can be incorporated into the press used to press the compression sleeve and connector body together.  
         [0065]     Referring now primarily to  FIG. 12 , it may be understood that pressing connector body  75  and compression sleeve  71  longitudinally together contracts the spacing between inner, rear shoulder wall  79  of the connector body, and rear wall  88  of the compression sleeve. This contraction causes ribs  99  of inner wall surfaces  89  of compression sleeve  71  to press in a longitudinally forward direction against the frusto-conically deformed outer wall surface of hose A, forcing shoulders  98  adjacent to ridges  99  in the inner wall surface of the compression sleeve to “dig in” to the outer wall surface of the hose, and those portions of the hose located between the ridges to cold flow into grooves  95  between the ridges. Thus installed, permanently attachable sanitary hose coupler  70  according to the present invention forms a fluid pressure-tight seal with hose A. Importantly, as shown in  FIG. 12 , the fluid pressure-tight seal between coupler  70  and hose A is devoid of any cavities in a liquid product flow path through bore B of the hose and bore  77  of the coupler; the absence of any such cavities guarantees that there are no places in the coupler which might serve as traps for liquid product.