Abstract:
A power operated pressure washer having a high pressure liquid supply hose with an inlet fitting formed with an axial stem having a central liquid passageway that can be connected to a pressure washer outlet fitting by a threaded retaining ring. As a feature of this invention, the retaining ring can be unscrewed from the pressure washer outlet for permitting the dissipation and venting of high pressure buildup within the hose while the retaining ring safely retains the hose fitting on the outlet. In one embodiment, the stem has a pair of axially spaced annular sealing members adaptable for sealing engagement with relatively smaller and larger size pressure washer outlets and the stems is formed with a transverse passageway for venting liquid from the central stem passageway around one of the sealing members, as an incident to unscrewing of the retaining ring, while the other sealing member remains in sealed engagement with the pressure washer outlet fitting.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application claims the benefit of U.S. Provisional Patent Application No. 60/809,600, filed May 30, 2006, which is incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to high pressure hose, and more particularly, to couplings for releasably connecting hose in high pressure hydraulic systems, such as hose used for connecting a pressure washer to a spray gun used for dispensing high pressure liquid generated by the pressure washer. 
     BACKGROUND OF THE INVENTION 
     Various forms of couplings are utilized for connecting high pressure hose to items, such as a pressure washer and dispensing gun, in high pressure hydraulic systems. In such systems, it is important that the couplings enable sealed connection between the hose and the pressure washer or spray gun for safe and reliable operation. From an economic and convenience standpoint, particularly in consumer operated pressure washer products, it is desirable that the hose couplings also permit use with various sized inlet and outlet fittings of the pressure washer and spray guns with which the hose is used. U.S. Pat. No. 6,779,745, assigned to the same assignee as the present application, the disclosure of which is incorporated herein by reference, discloses a high pressure hose with couplings adapted for versatile usage with different sized inlet and outlet fittings. 
     It is not only necessary that the couplings permit reliable safe connection of the hose to the pressure washer or spray gun, but that they enable safe uncoupling and disconnection of the hose in such systems, which can remain substantially pressurized following usage. For example, in pressure washer systems, following use of the pressure washer, it is common for pressure within the hose downstream of the pressure washer to remain at several thousand psi. Hence, uncoupling of the hose from the pressure washer under such conditions can create a danger to the user by virtue of sudden high pressure discharge from the coupling upon disconnection. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide high pressure hydraulic system with hose having couplings adapted for reliable safe coupling of the hose to an associated component in a high pressure system, as well as safe uncoupling of the hose from the component when the system remains in a highly-pressurized state. 
     Another object is to provide a high pressure hose as characterized above having couplings which permit uncoupling from a component of a high pressure liquid system without a dangerous sudden burst of high pressure fluid during such uncoupling. 
     A further object is to provide a high pressure hose of the foregoing type having couplings which are adapted to gradually diffuse high pressure liquid within the system during loosening and disconnection of the coupling from a component of a system following usage. 
     Still another object is to provide a high pressure hose of the foregoing type in which the couplings are universally adaptable for use with multiple sized fittings of associated components of a pressurized liquid system. 
     Yet a further object is to provide a high pressure hose of such type in which the couplings are adapted for economical manufacture and easy and reliable usage. 
     Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is an exploded perspective of a pressure washer with a high pressure extension hose in accordance with the invention connected between the pressure washer and the hose of a spray gun that controls liquid discharge from the pressure washer; 
         FIG. 2  is an enlarged fragmentary section of a coupling in accordance with the invention connecting the extension and spray gun hoses; 
         FIG. 3  is a fragmentary section, similar to  FIG. 2 , showing the hose coupling in a partially uncoupled condition, that permits safe venting of high pressure liquid within the system; 
         FIG. 3   a  is an enlarged fragmentary section illustrating the break of a seal and venting of high pressure liquid from the system as an incident to disconnection of the coupling as shown in  FIG. 3 ; 
         FIG. 4  is a fragmentary section, similar to  FIGS. 2 and 3 , showing the hoses fully disassembled from the coupling; 
         FIGS. 5-7  are fragmentary sections, similar to  FIGS. 2-4 , showing an alternative embodiment of hose coupling in accordance with the invention; and 
         FIGS. 8-10  are fragmentary sections, similar to  FIGS. 2-4  and  5 - 7 , showing another alternative embodiment of hose coupling in accordance with the invention. 
         FIG. 11  is a depiction of the extension hose in accordance with the invention being used between a spray gun and pressure washer; 
         FIG. 12  is an enlarged fragmentary section showing the hose in  FIG. 11  being connected to a spray gun inlet fitting; and 
         FIG. 13  is an enlarged fragmentary section showing the hose in  FIG. 11  being connected to a pressure washer outlet fitting. 
     
    
    
     While the invention is susceptible of various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now more particularly to  FIG. 1  of the drawings, there is shown an illustrative high pressure hydraulic system which includes a pressure washer  10 , a spray gun  11  having a flexible high pressure hose  12 , and an extension hose  13  connected between the pressure washer  10  and the spray gun hose  12 . The illustrated spray gun  11  is permanently secured to the downstream end of the flexible pressure washer hose  12 , which like the extension hose  13 , may be of a flexible reinforced construction of a known type suitable for withstanding liquid pressures generated by the pressure washer. The pressure washer  10  may be of a conventional type which has a gasoline or electric powered motor for operating a pump to generate a high pressure liquid discharge. The pressure washer  10  in this case has an outlet fitting  15  which may be of a conventional type, as disclosed in the afore-referenced patent.  FIG. 11  illustrates an alternate system where the outlet fitting  15  of the pressure washer is connected via extension hose  13  to fitting  16  of spray gun  11 . 
     For enabling connection of the spray gun hose  12  to the extension hose  13 , or directly to the pressure washer outlet fitting  15 , the spray gun hose  12  has a fitting  20  fixedly secured to the upstream end thereof. The fitting  20 , as depicted in  FIG. 2 , has a ribbed shank  21  that is forceably positioned into the end of the hose  12  up to and against a radial locating flange  22  of the fitting  20 . For positively securing the fitting  20  in the hose  12 , an annular ferule  24  is positioned about the end of the hose and has an annular retaining flange  25  that is deformed into an annular retaining groove of the fitting immediately adjacent the locating flange  22 . The fitting  20  has an outwardly extending connecting stem  26  which in this case includes a smaller diameter outer hub portion  28  and a relatively larger diameter inner hub portion  29  adjacent a radial retaining flange  30 . The stem  26  carries a pair of axially-spaced o-rings  31 , 32  within respective outwardly opening annular grooves formed in the stem. The outer o-ring  31  in this case has a smaller diameter than the o-ring  32 . 
     The illustrated extension hose  13  comprises a length of connector high pressure hose with connecting fittings  40  at its opposite ends which are identical in construction, and in this case, similar to the spray gun hose fitting  20 . The connecting fitting  40  has a hose connecting stem  41  at one end, a mating stem  42  at the other end, and an outwardly extending retaining flange  44 . The hose connecting stem  41  is a relatively small diameter ribbed member over which the hose is forcefully positioned into abutting relation to a locator flange  45 . For positively affixing the stem  41  to the hose  13 , a ferrule  46  is provided, which has a radial end wall  48  that is crimped cramped inwardly into an annular groove of the fitting  40  with the hose interposed there between. The mating stem  42  of the extension hose fitting  40  has a relatively small diameter terminal outer hub portion  50  and a larger diameter inner hub portion  51  and carries a pair of o-ring  54 , 55  in outwardly opening axially spaced grooves, with the outer o-ring  54  being smaller in diameter than the inner o-ring  55 . 
     For enabling releasable connection of the spray gun hose  12  with the extension hose  13 , an adapter  60  is provided which may be substantially similar to the adapter disclosed in the afore-referenced patent. The illustrated adaptor  60  has a central hub portion  61  with externally threaded cylindrical extensions  62 , 64  of common diameter extending coaxially outwardly from opposite sides of the hub  61 . The adaptor  60  is formed with an axial flow passage  69  which in this case comprises two separate cylindrical chambers  69 S,  69 L each communicating with each other from opposite ends of the adaptor. As set forth in detail in the aforesaid referenced patent, the chamber  69 S has a relatively small diameter (i.e., 14 mm.) corresponding to a smaller diameter pressure washer outlet and the second chamber  69 L has a relatively larger diameter (i.e., 15 mm.) corresponding to a relatively larger diameter pressure washer outlet. It will be understood that to assist in understanding certain of the discussions herein, references to pressure washers having a 14 mm. discharge outlet and components designed for use therewith sometimes have been designated with the appropriate reference numeral and the distinguishing suffix “S” (for small or 14 mm.). The larger 15 mm. pressure washer discharge outlet and components designed for use therewith sometimes have been designated with the appropriate reference numeral with the distinguishing suffix “L” (for large or 15 mm.). 
     The extension hose fitting  40  in this case, as shown in  FIG. 2 , is secured within the smaller diameter inlet chamber  69 S of the adapter  60 , and the extension hose fitting  20  is secured within the relatively larger diameter inlet chamber  69 L of the adapter. With the extension hose fitting stem  42  positioned in the relatively smaller diameter chamber  69 S, the smaller diameter annular seal  55  is in sealing engagement with an inner wall of the chamber  69 S and the larger diameter o-ring  55  is forced into sealing engagement with a chamfered annular end  70  the adapter  60 . For securing the extension hose fitting  20  within the adapter chamber  69 S, a threaded retainer ring  71  is provided about the end of the extension hose  13 , which engages the radial retaining flange  44  and draws in it to captive position as an incident to threaded engagement of the retainer ring  71  onto an externally threaded end of the adapter  60 . 
     The spray gun hose fitting  20 , as also depicted in  FIG. 2 , can be similarly connected to the adapter  60 , with the stem  26  being positioned in the larger diameter inlet chamber  69 L. The smaller and larger diameter hub portions  28 , 29  of the stem  26  in this case both are positionable into the larger diameter chamber  69 L with the larger diameter o-ring  32  being in sealing engagement with an internal wall of the chamber  69 L and the smaller diameter o-ring  31  guiding positionable movement of the stem  26  into the adapter  69 L. A threaded retainer ring  74  similarly is threadably engageable with an externally threaded end of the adapter  60  drawing the spray gun hose fitting  20  into captive secure relation to the adapter  60 . 
     During operation of the pressure washer  10 , the adapter  60  enables reliable high pressure communication of liquid from the pressure washer  10  through the extension hose  13  and spray gun hose  12  for controlled discharge and direction by the spray gun  11 . As indicated above, following operation of the pressure washer, a high pressure buildup remaining in the extension and pressure washer hoses can cause a sudden dangerous outburst of high pressure liquid upon disconnecting the hoses from the adapter or other fittings in the system. 
     In accordance with the invention, the hose fittings are adapted for gradually releasing a high pressure buildup within the hoses as an incident to uncoupling of the fittings so as to prevent injury to persons from sudden high pressure discharge. More particularly, the fittings have venting apertures which permit gradual venting and decompression of pressure buildup from the high pressure hoses while the retaining caps remain in secure threaded engagement with the coupling adapter. To this end, in the illustrated embodiment, the fittings  20 ,  40  each have a respective radial venting passageway  75 , 76  that communicates from the central liquid flow passage  69  of the adapter to an outer radial location between the axially spaced o-rings of the respective stem. 
     The radial venting passageway  76  of the extension hose fitting  40  communicates between the internal flow passageway  69  and outer location between the o-rings  54 , 55 . Upon loosening of the retaining ring  71 , as depicted in  FIGS. 3 and 3A , such as one or two turns, trapped pressure within the system tends to push the fitting  20  outwardly of the adapter  60  breaking the seal between the outer o-ring  55  and the chamfered end  70  of the adapter  60 . With the seal broken, high pressure will dissipate in a controlled fashion through the venting passageway  76  and between the o-ring  55  and chamfered edge  70  to atmosphere to gradually relieve the internal pressure. As an important aspect of the invention, it will be understood that it is important that the threaded connection between the retaining ring  71  and the adapter  60  is long enough to permit unscrewing of the retainer ring  71  a sufficient distance to break the seal between the o-ring  55  and the adapter chamfered end  70 , while the retaining ring  71  continues to securely retain the retainer ring  71  on the adapter  60 . This enables the slight break in the seal to be maintained sufficient to dissipate the pressure buildup without sudden outburst of pressurized liquid from the coupling. When the pressure buildup has fully dissipated, continued unscrewing of the retainer ring permits the extension hose fitting  40  to be removed from the adapter  60 , as depicted in  FIG. 4 . 
     In keeping with the invention, the spray gun hose fitting  20  similarly may be uncoupled from the adapter  60  while in a pressurized state, without sudden harmful discharge of high pressure fluid. In this case, the retainer ring  74  must be turned a sufficient number of turns to enable pressure within the system to move the stem  26  outwardly to the point that the seal is broken from between the o-ring  32  and the internal wall of the adapter chamber  69 L, as depicted in  FIG. 3 , thereby enabling high pressure fluid to be gradually dissipate in a controlled manner both from 1) the venting passageway  75  of the fitting  20 , and 2) the small space between the smaller o-ring  31  and the inner wall of the adapter chamber  69 L for ultimate escape to atmosphere through the broken seal between the larger o-ring  32  and the end of the adapter. Again, venting of high pressure buildup occurs while the retaining ring  74  remains in secure threaded engagement with the adapter  60 . Once the pressure buildup has been dissipated in such controlled and gradual fashion, the retainer ring  74  can be unscrewed further to remove the fitting  20  from the adapter  60 , as depicted in  FIG. 4 . 
     In keeping with the invention, it will be understood that the spray gun and extension hose fittings  20 , 40  may be universally used with different sized outlet fittings of the pressure washer  10  or fittings of other components of a pressurized hydraulic system such as the fitting  16  of spray gun  11  (see  FIGS. 11 and 12 ). For example, if the extension hose fitting  20  or  40  is to be connected to a smaller diameter outlet fitting of the pressure washer, such outlet having a  14  mm. diameter, the fitting may be connected to the outlet in the manner shown in  FIG. 13  with the o-rings  54 ,  55  creating a redundant seal when assembled, and with the venting passage  76  of the stem enabling gradual pressure discharge upon unloosening of the retaining ring from the outlet a sufficient distance to break the seal between the larger diameter o-ring  55  and the adapter  60 , while the retaining ring  71  retains threaded engagement with the outlet. Likewise, when the fitting  20  or  40  is used with a relatively larger diameter outlet fitting, such as a 15 mm. diameter outlet, the fitting may be connected to the outlet in the same manner that the fitting  20  connects to the larger diameter outlet chamber  69 L in  FIG. 2 , with the larger diameter seal  32  being in sealing engagement within an internal wall chamber  69 L and which upon loosening of the retaining cap, permits controlled venting both through the venting aperture  75  and from the smaller diameter o-ring  32  and the adapter. 
     With reference to  FIGS. 5-7 , an alternative coupling arrangement is shown wherein items similar to those described above have been given similar reference numerals with the distinguishing suffix prime (′) added. The spray gun hose fitting  20 ′ and the extension hose fitting  40 ′ in this case have a single sealing o-ring  32 ′,  55 ′, respectively, corresponding to the larger diameter sealing o-rings in the previously described embodiment. The fittings  20 ′,  40 ′ again have connecting stems  26 ′, 42 ′, respectively, which each include a relatively larger diameter inner hub portion  29 ′,  51 ′, and an outer smaller diameter hub portion  28 ′,  50 ′, respectively. The o-rings  32 ′,  55 ′, are disposed between the larger and smaller diameter hub portions. 
     With the coupling fully assembled in the adapter  60 ′, as depicted in  FIG. 5 , the o-ring  55 ′ of the extension hose fitting  40 ′ is maintained in biased sealing engagement with a chamfered end  70 ′ of the adapter  60 ′ by the retaining ring  71 ′. The connecting stem  26 ′ of the extension hose fitting  20 ′ is positioned with the hub portions  28 ′,  29 ′ both within the larger diameter chamber  69 L′ of the adapter  60 ′ and with the o-ring being in sealed engagement with an internal wall of the chamber  69 L′ and retained in such position by the threadedly engaged retainer ring  74 ′. 
     To uncouple the coupling while in a pressurized state, the retaining ring  71 ′ of the extension hose fitting  40 ′ may be loosened, such as by one or two turns, to permit pressurized fluid within the system to break the seal between the o-ring  55 ′ and the chamfered end of the adapter  60 ′ and permit gradual control venting of the pressure buildup to atmosphere, while the retaining ring  71 ′ secures the coupling in such loosened condition. Alternatively, the retaining ring  74 ′ of the extension hose fitting  20 ′ may be loosened by turning up the retaining ring  74 ′ a sufficient number of turns to cause pressure within the system to move the stem  26 ′ and o-ring  32 ′ sufficiently outwardly of the adapter chamber  69 L′ to permit breakage of the seal between the o-ring  32 ′ and the wall of the chamber  69 L′ to enable controlled venting of the pressure buildup to atmosphere while the retaining ring  74 ′ secures the coupling in such loosened condition. Again, it will be appreciated by one skilled in the art that the fittings  20 ′,  40 ′ can be universally used with different sized outlet fittings of a pressure washer or other components of a pressurized hydraulic system in a similar manner. 
     With reference to  FIGS. 8-10 , there is shown another alternative embodiment of a high pressure hose coupling in accordance with the invention wherein items similar to those described above have been given similar reference numerals with the distinguishing suffix “double prime” (″). The spray gun hose fitting  20 ″ and the extension hose fitting  40 ″ in this case each have connecting stems  26 ″, 42 ″ with a pair axially spaced o-rings  31 ″, 32 ″ and  54 ″, 55 ″ similar to the embodiment of  FIGS. 2-4 , but without a radial venting passageway. When in the assembled condition, as depicted in  FIG. 8 , the o-rings similarly cooperate with the adapter  60 ″ to provide a sealed coupling during operation of the pressure washer. 
     To release pressure buildup following usage of the pressure washer, the retaining ring  74 ″ of the extension hose fitting  20 ″ may be turned a turn or two to permit pressure within the system to break the seal between the o-ring  32 ″ and the chamfered end of the adapter  60 ″ to permit controlled venting of the internal buildup pressure in the system through a small space between the smaller diameter o-ring  31 ″ and the internal wall of the chamber  69 L″ and the pressure break between the larger diameter o-ring  32 ″ and the end of the adapter  60  to atmosphere. Again, the retaining ring  74 ″ remains in threaded engagement with the adapter  60 ″ to maintain the controlled released of the pressure buildup. 
     Alternatively, pressure buildup within the system may be relieved following usage by unscrewing the retainer ring  71 ″ of the extension hose fitting  40 ″ sufficiently to remove both the larger diameter o-ring  55 ″ and the smaller diameter o-ring  54 ″ from sealed engagement with the chamber  69 S″, while the retaining ring  71  remains in threaded engagement with the adapter  60 ″. Again, the fittings  20 ″ and  40 ″ can be universally used with different sized outlet fittings of the pressure washer or other components of the pressurized system for permitting gradual release of pressure buildup as an incident to uncoupling of the fittings. 
     From the foregoing, it can be seen that a high pressure hydraulic system is provided, such as a pressure washer system, having hose with couplings adapted for reliable coupling of the hose to an associated component of the high pressure system, as well as safe uncoupling of the hose from the component when the system remains in a highly-pressurized state. The couplings permit the gradual diffusion of high pressure within the system during loosening and disconnection of the system without dangerous sudden bursts of pressure fluid. The couplings further are relatively simple in construction and are adapted for universal use with multi-sized fittings of associated components of the pressurized liquid system.