Abstract:
A safety lock for a spray nozzle assembly for an airless, high pressure spray device, and more particularly to safety locks or guards for reversible, rotatable spray nozzles assemblies, optionally provided with a tip guard.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a safety lock for a spray nozzle assembly for an airless, high pressure spray device, and more particularly to safety locks or guards for reversible, rotatable spray nozzle assemblies, optionally provided with a tip guard. 
       BACKGROUND OF THE INVENTION 
       [0002]    Reversible, rotatable spray nozzle assemblies are widely used by spray devices, such as for high pressure, airless spraying of paint and other fluids. In a typical reversible spray nozzle assembly, a small spray nozzle, bore or tip is carried in a cylindrical, rotatable nozzle shaft. The nozzle shaft can be rotated 180 degrees, thereby reversing the direction of paint flow through the nozzle, bore or tip for cleaning nozzle obstructions. Typically the spray nozzles or tips are interchangeable with other spray nozzles carrying nozzles of various diameters and capacities. 
         [0003]    Reversible spray nozzles or tips are generally utilized in hydraulic or airless spray painting or coating, wherein paint under high pressure is supplied to a spray gun and forced through a spray tip or nozzle, to aid in cleaning clogs that may form at the nozzle. Clogs can form due to the nature of the spray devices, wherein it is necessary for the spray opening in the spray nozzle be very small so that as the paint reaches the spray tip under high pressure and low velocity, it is accelerated through the spray opening at a high velocity and low pressure thereby forming a spray suitable for painting. Owing to the small size of the spray opening, the spray nozzle is susceptible to clogging. By providing a reversible tip, the spray nozzle can be turned generally 180 degrees and the paint or particles causing the clog can be discharged. 
         [0004]    When using reversible spray nozzles or tips, user safety must be the most important concern. The spray that emanates from the nozzle of the spray device has the highest velocity and narrowest stream, and provides a risk of injury to the user. In view of this situation, prior spray devices have included various styles of spray guards to prevent the user&#39;s body from being hit by the spray jet near the spray nozzle orifice. 
         [0005]    An additional problem spawning from the use of the reversible spray nozzle or tip is that it is possible to rotate the spray nozzle out of position, especially if the nozzle handle is bumped or jarred in the course of handling or moving the spray device. It is also possible for a user to fail to properly align and rotate the nozzle completely into the correct position before activating the spray devices. These circumstances can yield a condition, wherein the nozzle is not properly aligned when fluid flow is activated, that can result in accidents that can range in severity from nuisances such as erratic paint disbursement to injuries from skin or eye irritation, blindness, trip and falls, to possibly death. 
         [0006]    U.S. Pat. No. 6,481,640 to Carey et al. relates to a saddle seal and washer insertion tool for airless paint spray tip assemblies having a housing containing a reversible tip holder of the type having cylindrical barrel with a handle formed of a polymer, located on and positioned generally transversely of the barrel, the housing having a longitudinal through bore for permitting delivery of paint, and a transverse bore for receiving the barrel of the tip holder, the insertion tool formed integrally with an end of the handle, the tool having a first portion with a width conforming to an internal diameter of the washer and a second portion extending beyond the first portion with a width conforming to a diameter of a bore in the saddle seal such that the washer can be received on the first portion and the saddle seal received on the second portion for alignment and installation into the housing. 
         [0007]    U.S. Pat. No. 6,390,386 to Krohn et al. relates to a reversible airless spray tip. A positioning detent on the spray tip carrier handle snaps positively into place when a nozzle carrier is rotated into spray position, indicating that the tip is properly positioned for spraying. A piston seal has a slot-like fluid passage, which is preferably substantially rectangular in cross section. A rearward end of the piston seal is sealed by a resilient ring compressed directly against the face of an attached spray gun. A tip retainer is expanded by swaging after insertion, which forces a lip into a mating slot. The tip retainer also has an expanded chamber which diffuses reverse fluid flow for safety. 
         [0008]    U.S. Pat. No. 5,749,528 to Carey et al. relates to a reversible spray tip or nozzle used with a spray gun or like device for hydraulically atomizing and spraying liquids such as paint. The spray tip includes a plastic housing having a forward extending spray tip guard integral therewith, a cylindrically shaped rotatable turret member diametrically received for rotation in the housing and having a diametric bore therethrough for receipt of a spray tip insert, and an elongated seal insert axially received in the housing upstream from the turret member. A securing nut rotatably mounted to the housing at the spray gun end thereof secures the reversible spray tip to the discharge end of the spray gun. The enhanced sealing effectiveness of the reversible spray tip permits effective sealing of the assembly by finger tightening of the securing nut. 
         [0009]    U.S. Pat. No. 5,285,965 to McCutcheon et al. relates to a tip guard is provided to reportedly protect a user of an air-assisted airless paint spray gun from injury. The tip guard has a base having a shoulder and an aperture adapted for engagement to the air cap and tip of an air-assisted airless paint spray gun. The base further has a pair of transition portions extending axially forward from said aperture, where notches formed in the transition portions are adapted to engage the forwardly-extending horns of the air cap of an air-assisted airless paint spray gun. Each transition portion further has a pair of vanes extending forwardly and radially outwardly from the transition portion, where each of said pair of vanes is then joined by a crossbar. 
         [0010]    U.S. Pat. No. 4,165,836 to Eull relates to an apparatus for attachment to a hand operated spray gun, comprising a cylindrical rotatable member having a spray orifice therein, which is rotatable between a spraying position and an orifice cleaning position, the rotatable cylindrical member having a metallic sealing member surface of matching shape and adjacent thereto, and a further resilient sealing member for permitting leakproof attachment to a spray device. The rotatable spray member is actuably coupled to a safety tip guard so as to become disassembled if the safety tip guard is removed. 
         [0011]    U.S. Pat. No. 3,952,955 to Clements relates to an apparatus for fitting over the spray tip end of an airless paint spray gun, wherein the apparatus comprises a pair of forwardly projecting ears and a narrow slotted region opening said spray tip, and is adapted for key alignment with the spray tip. 
         [0012]    Even through some prior art devices include features such as rotation stops or limits, such devices can be subject to user error and do not solve the problem of transverse misalignment in a direction perpendicular to the axial spray flow direction through the nozzle or tip. 
       SUMMARY OF THE INVENTION 
       [0013]    In view of the above, it would be desirable to provide such spray devices with a safety feature to prevent misalignment of the spray nozzle or tip both in the axial direction of spray flow and in a direction perpendicular to the axial spray flow direction. 
         [0014]    It is an object of the present invention to provide a spray device having a rotatable spray nozzle or tip with a safety lock connectable thereto that protects the spray nozzle and prevents the same from moving out of spraying alignment. 
         [0015]    A further object of the present invention is to provide a safety lock that is connected to a portion of the spray device other than the spray nozzle and is movable into and out of engagement with the spray nozzle in order to lock the spray nozzle in a spraying position. 
         [0016]    Yet another object of the present invention is to provide a safety lock connected to one or more of a spray guard, a body of the spray device or a portion of a spray nozzle assembly and movable to lock the position of the spray nozzle. 
         [0017]    An additional object of the present invention is to provide a safety lock that surrounds the handle of the spray nozzle and prevents the spray nozzle from being misaligned. 
         [0018]    An additional object of the present invention is to provide a safety lock having a contour closely fitted to the exterior dimensions of the handle and fits thereover in order to provide a physical stop to prevent the handle from rotating as well as visual notice to a user that the handle is constrained and in a safe position for applying a coating. 
         [0019]    In one aspect of the present invention spray device is disclosed comprising a rotatable, reversible spray tip, the spray tip having a handle for rotating the spray tip relative to a body of the spray device, a safety lock operatively connected to a) the body of spray device, b) a safety guard of the spray device, or c) a portion of a spray tip assembly of the spray device, the safety lock having a cover substantially conforming to the shape of the handle such that the cover is selectively engagable with the handle to prevent the handle from rotating out of a spraying position. 
         [0020]    Another aspect of the present invention discloses a spray nozzle assembly with a safety lock for a spray device, comprising a base connectable to the spray device, the base having an orifice to allow a coating to pass through the base, the base having a bore extending substantially transverse to the orifice, a spray tip having a shaft located in the base bore and rotatable therein, the spray tip shaft having a bore to allow a coating to pass therethrough when aligned with the base orifice, the spray tip having a handle, and a safety lock having a connector attached to a portion of the spray nozzle assembly, the safety lock having a cover that is engagable with the handle in a locked position that prevents the handle from being rotated such that the shaft bore is out of alignment with the base orifice. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]    The invention will be better understood and other features and advantages will become apparent by reading the detailed description of the invention, taken together with the drawings, wherein: 
           [0022]      FIG. 1  is a side elevational view of one embodiment of a safety lock of the present invention connected to a spray guard affixed to one embodiment of a spray device; 
           [0023]      FIG. 2  is a top plan view of a portion of the spray device, spray guard and safety lock illustrated in  FIG. 1 ; 
           [0024]      FIG. 3  is a side elevational view of a further embodiment of a safety lock of the present invention connected to a portion of a spray nozzle assembly; 
           [0025]      FIG. 4  is a top view of a portion of the spray device, illustrating a further embodiment of a safety guard and safety lock; 
           [0026]      FIG. 5  is a side elevational view of  2  a further embodiment of a safety lock of the present invention form-fitted to a shape of a handle of the spray nozzle; and 
           [0027]      FIG. 6  is a top view of a further embodiment of a safety lock of the present invention including a spring-biased pin releasably accommodated in a recess of the spray nozzle assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    This description of preferred embodiments is to be read in connection with the accompanying drawings, which are part of the entire written description of this invention. In the description, corresponding reference numbers are used throughout to identify the same or functionally similar elements. Relative terms such as “horizontal”, “vertical”, “up”, “down”, “top” and “bottom” as well as derivatives thereof (e.g., “horizontally”, “downwardly”, “upwardly”, etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and are not intended to require a particular orientation unless specifically stated as such. Terms including “inwardly” versus “outwardly”, “longitudinal” versus “lateral” and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation or a portion of the device, as appropriate. Terms concerning attachments, couplings and the like, such as “connected” and “interconnected”, refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. The term “operatively connected” is such an attachment, coupling or connection that allows the pertinent structures to operate as intended by virtue of that relationship. 
         [0029]    Referring now to the drawings,  FIG. 1  illustrates one embodiment of a spray device  10  having a spray nozzle assembly  20  connected thereto, the assembly  20  including a rotatable spray nozzle or tip  22  and a safety lock  50  mated to the spray nozzle or tip  22  that prevents the spray nozzle or tip  22  from becoming misaligned out of a spraying or cleaning position. 
         [0030]    The spray device  10  can be of any construction and is preferably an airless high pressure sprayer that provides a relatively high velocity stream or jet of a coating material, for example paint for use in painting or coating materials or objects, e.g. walls, ceilings, substrates, etc. The spray device has frame  12  that has a coating inlet port  14  and an outlet port  16  preferably having a threaded outer surface for connection to the spray nozzle assembly  20 . A trigger assembly  18  controls the flow of the coating through the outlet port  16 . Suitable spray devices are available from Graco of Minneapolis, Minn., and Titan Tool of Plymouth, Minn. The spray device  10  may be equipped with a safety device, such as but not limited to a trigger lock  19  to prevent accidental discharge of the coating from the outlet port  16 . 
         [0031]    The spray nozzle assembly  20  in one embodiment includes an internally threaded retaining nut  24  optionally including a gripping surface such as a scalloped and/or angled exterior that allows a user to hand mount and/or tool mount the spray nozzle assembly  20  on the spray device  10 , generally at the outlet port  16 . One end of a base  26  of the spray nozzle assembly  20  is operatively connected to retaining nut  24  and another end is operatively connected to the spray guard  40 . A cylindrical spray nozzle or tip  22  is slidably and rotatably located in transverse bore  28  of the base  26 . The spray tip  22  can be rotated into a spray position as illustrated or in a reversed cleaning position generally 180° rotated from the position shown, by turning the attached handle  30 . 
         [0032]    Base  26  generally includes a longitudinal bore, a fluid passage  27  that is substantially perpendicular to the transverse bore  28  which it intersects. The longitudinal bore or fluid passage  27  preferably has or is fitted with base seal, with the seal having a generally concave sealing surface that mates with the cylindrical contour of the shaft  32  of the spray tip  22 . Base  26  may be provided with or contain a seal at the rearward end of the base that can be compressed between the end of the base  26  and the outlet port  16  of the spray device  10  to prevent leakage with the seal obviously including a bore therethrough allowing for passage of the coating fluid. 
         [0033]    Fluid passage  27 , having any desired cross section such as a rectangular cross-section or circular cross-section, extends longitudinally through the base  26 . When the rotatable spray tip  22  is rotated into the spraying position or the cleaning position, the shaft bore  34  aligns axially with the fluid passage  27  along longitudinal axis  36 . As pressurized fluid is supplied from the spray device  10 , the fluid or coating is allowed to flow through outlet port  16  of spray device  10  then through spray nozzle assembly  20  via fluid passage  27  and base  26  and further through shaft bore  34  of spray tip  22 , and emerges in a spray pattern along longitudinal axis  36 . 
         [0034]    As known in the art, the shaft  32  of the spray tip  22  slidably passes through an opening in the base  26  of the spray nozzle assembly  20  to insert into the transverse bore  28  of base  26 . Handle  30  of spray tip  22  is connected to shaft  32  in any suitable manner. Shaft  32  co-rotates with handle  30 . The handle enables the user to rotate the shaft  32  between the spray position and a reverse flow, cleaning position, as well as any position therebetween. 
         [0035]    Spray guard  40  includes a body  42  and one or more support arms  44 , preferably four support arms  44  extending outwardly and forwardly from spray guard body  42 . Two or more arms  44  may be connected by a tip guard  46  which can be in the form of an aerodynamic air foil, if desired. The spray guard  40  helps to prevent objects, especially a user&#39;s hand or other portion of the user&#39;s body from coming into contact with the relatively high velocity spray jet near the nozzle assembly  20 , generally where the jet velocity is highest and the stream most narrow. The spray guard  40  generally serves as a warning and establishes a safe boundary for the user. 
         [0036]    While the spray tip may be provided with a stop such as a locking cam element, see for example U.S. Pat. No. 5,749,528 herein incorporated by reference, in an effort to prevent rotation of the spray nozzle shaft  32  out of alignment, such features are not always reliable. For example when a user sets the spray device  10  down or bumps an object with the spray device  10 , the shaft  32  can rotate and the shaft bore  39  can become misaligned with the longitudinal axis  36  and the base bore  28  of the spray nozzle assembly  20 . If the user does not realize the misalignment and activates the trigger mechanism  18  of the spray device, the coating can spray out between the shaft  32  and the base  28  of the spray nozzle assembly  20  and cause the user to be injured by the spray and/or damage to the surrounding area. 
         [0037]    In order to solve this problem and prevent accidental misalignment, the spray device  10 , and more preferably the spray tip assembly  20  is provided with safety lock  50  that prevents the spray tip  22 , and particularly the handle  30  thereof from being rotated out of spraying alignment. 
         [0038]    The safety lock  50  is a formed housing having a cover  54  that closely conforms to and generally fits over in some embodiments, the handle  30  of the rotatable spray tip  22 . In one embodiment, the cover preferably includes at least one side  56 , see  FIG. 2  having a longitudinal length extending along a distance, preferably the entire distance, of the longitudinal length of the handle  30  that prevents the handle  30  from being rotated out of alignment with the longitudinal axis of the spray nozzle assembly  20 . In additional embodiments, the safety lock  50  is provided with a top  55  wherein when the safety lock  50  is in a connected position contacts a top side or outer end of the handle and prevents the spray tip  22  and handle  30  thereof from being dislodged or backed out of bore  28  whereby the shaft bore  34  would be misaligned with the fluid passage  27  of base  26 . In a preferred embodiment both the top  55  and side  56  are provided on safety lock  50 , thereby forming a cover, shield or protective guard around the outer surface of handle  30 . In some embodiments, the one or more sides  56  and top  55  of safety lock  50  are integrally formed and can be in the form of a cap or the like. 
         [0039]    Safety lock  50  includes a base  51  that is connected to one or more of a portion of the spray nozzle or tip assembly  20  and the spray device  10 .  FIGS. 1 and 2  illustrate the base  51  connected to the spray guard  40 , namely the tip guard  46  of spray tip assembly  20 .  FIG. 3  illustrates safety lock  50  having base  51  connected to the frame  12  of the spray device  10 . Base  51  is connected to the spray device or spray tip assembly in any suitable manner such as by fastening, gluing, welding, etc. In one embodiment the base  51  is connected to the housing by a hinge system that allows the safety lock cover  54  to be moved out of the way, to an “unlocked” position, to allow adjustment of the spray tip  22 . 
         [0040]    Base  51  includes a connector  52  that allows the cover to be movable in relation to the portion of the base connected to the spray nozzle assembly  20  or spray device  10 . Preferably the connector  52  is in the form of a hinge or pivot. When the safety lock is formed out of a polymer, in one embodiment the connector  52  can be a living hinge. Connector  52  allows the cover  54  to be moved into a locked position and an unlocked position, for example as illustrated utilizing dashed lines in  FIG. 2  whereby the handle  30  is allowed to be rotated by the user. 
         [0041]    In a preferred embodiment, the safety lock  50  is provided with a locking mechanism or lock system  58 , such as illustrated in  FIG. 2  that maintains the cover  54  in a position secured to the spray device  10  or spray nozzle or tip assembly  20  such that the handle  30  of the spray tip  22  cannot be rotated or misaligned. Lock system  58  in one embodiment includes a projection and/or detent. For example as illustrated in  FIG. 2 , the end  57  of safety lock  50  includes a projection that mates with a recess of the locking segment connected to the base  26  of the spray tip assembly  20 . 
         [0042]    The safety lock  50  prevents the need of visual notice to the user that the handle  30  is in its desired position and also prevents the handle  30  from being dislodged accidentally by the user. Safety lock  50  can be formed of any suitable material, such as one or more of a polymer, metal, or the like. 
         [0043]      FIG. 4  illustrates a further embodiment of the safety lock  50  of the present invention including a base  51  having a connector  52  connected to the spray nozzle assembly  20 , namely the spray guard  40 . The safety lock  50  includes a snap fit connection  60  that releasably fastens the cover  54  to the spray device  10  to prevent movement of the rotable spray tip  22 . The snap fit connection generally includes an indent or recess  62  which matable receives a projection  63 . 
         [0044]      FIG. 5  illustrates a portion of the safety lock  50  having a body that closely conforms to a portion of the outline or shape of the rotable spray tip  22 , specifically handle  30  thereof. 
         [0045]      FIG. 6  illustrates a further embodiment connecting a safety lock  50  to a portion of the spray device  10 , namely spray guard  50 . A first end of the safety  50  is connected to arm  44  of spray guard  40  by a connector  52 , generally in the form of a hinge. Safety lock  50  also includes a lock system  58  including a knob  66  connected to a shaft  65  extending through a portion of the body of the safety lock  50  that has a pin  69  located at a second end of the shaft. A spring  64  biases the pin in a direction such that it can be fixed in recess  68  connected to a portion of the spray guard  40 . When the safety lock body is moved into a locked position preventing movement of the handle  30 , the pin is affixed in recess  68 . Knob  66  can be utilized to release the pin from the recess  68 . 
         [0046]    While in accordance with the patent statutes, the best mode and preferred embodiment have been set forth, the scope of the invention is not limited thereto, but rather by the scope of the attached claims.